Thursday, July 27, 2006

Torpedo Ray Injury

Frequent correspondent, Jim Grier calls our attention to an interesting posting on one of the boards about a torpedo ray injury. This was posted on the 'scubadiving' board by "TexasTechdiver" with a follow-up posting. It is an interesting account of a commercial diver who was inspecting a pipeline looking for a small oil leak. He called that he was in trouble, felt something like electricity and shock, then became silent. The video that he was wearing showed a stationary sea floor so the rescue diver immediately went down and retrieved the unconscious diver who had thrown up in his Kirby-Morgan hardhat. He was placed in the chamber and the dive ship unmoored and set sail for the coast, in order to decompress. They stabilized him and he was coherent but didn't know what had happened.

The video was retrieved from the boat and reviewed, and showed, moments before the diver lost consciousness, the approach of a sizeable torpedo ray. The sound indicated four separate electrical discharges from the ray that knocked the diver cold. He was lucky to be in a surface supplied hardhat rig, because on SCUBA he would be dead.

The diver is OK. He's getting an extensive workup looking for possible reasons why the extreme reaction to the electrical shocks. Everyone agrees he's very fortunate to be alive, and that the reaction on the dive crew to the incident was 100%. It's nice when things work out. It is thought that the reasons for the attack was that it was night and the ray was attracted to the diver's helmet light.

In a followup posting, TexasTechdiver relates a conversation with a dive accident consultant in which he talked to the consultant that was called in to investigate the torpedo ray incident, who related the debrief of the diver. The diver reported feeling electrical "tingles", then got hit the first time by the ray. The guy monitoring the diver asked how he was, and the diver said he was ok, but didn't know what had hit him. Then he reported feeling tingles again, and got hit again. He said "electricity" and "fish" then got hit a third time. By then he was out and keeling over. He was hit a fourth time, and that was it. The relief diver got down to him within eight minutes of the first hit, which was fortunate, as the stricken diver's helmet was filling with water.

Also, these rays are apparently far less electrically "active" in the day time, which might explains our being able to play with them and living to tell about it.

The medical exam pretty much ruled out any weird pathology on the part of the diver that would have contributed. He was healthy. He has an irregular heartbeat now, and they'll shock him and try to get him lined back out.

The Pacific electric ray (Torpedo californica) can be distinguished by its two dorsal fins and lack of a venomous spine on the tail and can muster up to 50 volts of electricity - enough to stop the heart of a human. Apparently the creature can send a 'bolt' of electricity toward a perceived threat - causing discomfort or pain, so touching the animal is not necessary for an injury.

The bigger Atlantic torpedo ray, occurring from Nova Scotia to Florida and beyond, is even more powerful. It can measure six feet across and weigh 200 pounds. Beachgoers, however, have nothing to fear from either of these species. They live in deep, cold waters and are mostly active at night. Fishermen occasionally catch the Atlantic torpedo in their trawls. Pulling up the net, their hands tingle. They know a ray is in the net before they even see it.

Jay Sisson, a diver working with Wood's Hole has the following to say about this interesting creature.
"I was shown your 'Torpedo Ray Injury" story by our DSO Terry Rioux (I work as a scientific diver for the Woods Hole Oceanographic). A couple years back I was hit by an Atlantic torpedo, twice. I never saw what hit me and my buddy Glenn witnessed all of it, then told me about it later. I was momentarily paralyzed by each hit but suffered no lasting injury. I believe Glenn estimated it's wingspan about 5 ft.
The location was in 52' of water about 1.5 nm south of Martha's Vineyard, at a research tower we maintain there. Torpedo was on the bottom near one of the piles."

Jay Sisson
Woods Hole Oceanographic Inst.
Woods Hole, MA 02543

Wednesday, July 26, 2006

Inspiration for 'Men of Honor' dies - Carl Brashear was first black U.S. Navy diver

Navy diver Carl Brashear lost a leg in 1966 helping to recover a lost hydrogen bomb.

Carl M. Brashear,75, the first black U.S. Navy diver died Tuesday at the Naval Medical Center Portsmouth of respiratory and heart failure. He was the diver who was portrayed by Cuba Gooding Jr. in the 2000 film "Men of Honor". Retired from the Navy in 1979 after more than 30 years of service, he was the first Navy diver to be restored to full active duty as an amputee, the result of a leg injury he sustained during a salvage operation for a nuclear weapon in 1966 in waters off the coast of Spain.

In 1954 he was accepted and graduated from the diving program, and went on to train for advanced diving programs before his 1966 incident.

Monday, July 24, 2006

Last Call to Receive Complimentary New Edition of Ocean Realm

Richard Stewart, Publisher and Editor-in-Chief of the Ocean Realm Journal, has informed us the new edition of Ocean Realm has finally arrived from Singapore and is on the dock yards of Long Beach, California. This new edition is a beautiful, high-quality color book with more than 107 pages of the best quality photography and content available. If you have not yet sent Ocean Realm your address this is the final call to receive a complimentary copy with free shipping. Please respond as soon as possible to; You will receive a bulk mailed copy within 2-3 weeks.

For What It's Worth - Hyperactive Gag Reflex Remedy

Here is a letter that we thought we'd pass on for those of you suffering from a hyperactive gag reflex. There must be a lot of you because we get numerous hits on our web page about this at .

"FYI in case it may help others:

I came across your web site a month ago while researching about the severe gag reflex problem that has prevented me from snorkelling for the past several years. I discovered only a week ago that my problem completely disappears if I wear a wristwatch while snorkelling! I'd stopped wearing watches in the water years ago because I'm rough on them and they unpredictably develop leaks.

The eureka moment for me came when a friend told me she'd worn "Sea-Band" on her wrists and experienced no sea-sickness on a recent cruise even though she's prone to nausea. Those bands are worn where one would place a wrist watch! Because of the neighbour's "Sea Band" experience, I bought a new water-tight watch which I now wear while snorkelling and much to my delight the gag problem has completely disappeared! "

My response: A study of many divers would be needed to show a significance.

I'll pass this on as a possibility.


Dr. Larry Stein, our resident diving dental consultant, has the following note about the gag reflex:
I saw the article on your site about the gag reflex. A number of compounding pharmacies make and "electrolyte tablet" that is supposed to suppress the gag reflex. It is supposed to be useful for giving anesthetic, taking impressions. swallowing tablets, performing oral hygiene.

This suppresses the reflex rather than eliminating it. I don't want to imagine the outcome of a diver with a suppressed reflex suddenly wearing off under water.

Here is a copy of some of the text from a pharmacy website and a journal reference:

Suppressing the Gag Reflex

The gag reflex can cause a patient considerable discomfort as well as interfere with dental procedures. An electrolyte tablet administered and retained intraorally a few minutes before the start of a procedure can suppress the gag reflex, allowing a mandibular block to be given with much greater ease, which further reduces the gagging reflex.

Tablets can be prescribed for home use for patients who can not properly perform oral hygiene procedures due to the gagging problem. Severe gaggers may need to repeat a dose in 15 to 20 minutes. (Dent Today. 1991 Dec;10(9):68-71)

Some patients and dentists prefer to use electrolyte lollipops.

Sunday, July 23, 2006

UHMS Announcements

8 NEW CLASSIFIEDS were listed

The National Board of Diving and Hyperbaric Medical Technology (NBDHMT) launches their new website (

The new site has been designed so that it is more user friendly and provides the information that you need and want. As you navigate around the website you will find a short “History of the NBDHMT”, some information on “Who we are”, a “Resource Manual” for CHT’s, DMT’s and CHRN’s, the “Testing Schedule”, “Approved Training Facilities”, an “Online Store”, and a list of our “Board of Directors” complete with email addresses and a “Contact” page. The Resource Manuals contain all of the information, with forms, that you need to attain your certification/recertification. You can download these manuals and forms to your files and use them as a quick reference. A listing of all members certified through the NBDHMT will be added to the website in the near future.

If you have any suggestions as to how we can make this website more useful please don’t hesitate to contact us.

Paul C. Baker, CHT
NBDHMT, President
1816 Industrial Blvd.
Harvey, LA 70058
fax: 504.366.1029

Undercurrent Online Update

Dive News
July 18, 2006

Malaria Risk in the Bahamas: In June, 18 people tested positive for malaria on Great Exuma Island in the Bahamas. Of these, 2 were from the U.S., 1 from Canada, and 1 from Germany. The Centers for Disease Control ( is temporarily recommending that travelers to Great Exuma take chloroquine, an antimalarial medication, as a preventative (it requires a prescription), and use mosquito repellents containing 30 to 50 percent DEET. No cases of malaria have been reported beyond Exuma and there are no health advisories for other islands. (Centers for Disease Control, July 17)

See also: Travel Medicine
Biting Insects, Malaria and Lariam

Scubapro Recalls X650 Second Stages: A serious manufacturing error could cause the cover and diaphragm to become dislodged, interrupting air flow underwater: Affected X650 regulators have been sold overseas since 2004 and in the U.S. since mid-2005. Owners should contact Scuba Pro at (800) 808-3948 between 8 a.m. and 5 p.m. PDT, Monday through Friday, or visit their website at The company promises to send out a free replacement regulator within 30 days.

Dangerous Error in Suunto Computer Software: Certain models of Suunto's D6 and D9 wrist computers have a software bug that may cause them to track time wrong when the computers automatically recalibrate to the correct time, or when the user updates the seconds in set mode. Suunto estimates these models will malfunction one out of 167 dives. When the error occurs, the computer shorts a dive by 25 percent and the surface interval by 25 percent. An hour dive would show as 45 minutes, an hour surface interval as 45 minutes. The error could seriously affect decompression requirements. The products affected are: D9, serial numbers 62102582 and below, and D6, serial numbers 62103693 and below. See Return it to your dealer or e-mail the Suunto Help Desk at Or call 1 800 543 9124 in the USA and Canada. Suunto is also providing the free update for computers purchased through gray marketers such as Leisure Pro.

Big Animal Encounters: No trip leader offers more thrilling trips for serious photographers than award-winning photographer Amos Nachoum. He's offering two in May 2007 to Malpelo and Cocos Islands, the first led by Dr. Sylvia Earle, a leading marine environmentalist and National Geographic resident scientist, the second by Dr. Kathryn Sullivan, astronaut and environmentalist. Boats are the SeaHunter and UnderSea Hunter. Undercurrent subscribers will get a five percent discount and free Nitrox. Contact him at or phone 415 923 9865. Visit

Fiji Fish Poisoning: Ciguetera poisoning can provide severe bends-like symptoms – heavy legs, exhaustion, tingling, prickling or numbness of the skin, abnormally low blood pressure, and slower than normal heart rate – that can last for months. It comes from eating affected fish, normally barracuda and larger fish that get it by ingesting smaller fish carrying the toxin. Though uncommon, it occurs worldwide cannot be detected in the flesh of the toxin-carrying fish. Undercurrent readers and others at the Kadavu Dive Resort in Fiji were struck after a fish dinner in late June. They didn't get proper treatment and are still reporting serous symptoms . See the full story in the August issue, as well as how to treat it should you encounter it.

See also:
Ciguatera references
50 references concerning ciguatera. ... [Ciguatera: from the etiology of the phenomenon to the treatment of its symptoms] ...

Ingested Toxins
CIGUATERA. The toxin, icthyosarcotoxin, is heat stable, lipid soluble and comes from the dinoflagellate Gambierdiscus toxicus. It is common in the tropics, ...

Help Save Coral Reefs: Undercurrent has raised more than $7000 for important projects to stop poaching and preserve reefs in Belize and Fiji. We need to double that amount. Please give back to the reefs you love my making a tax deductible contribution at We will send you a receipt acknowledging your tax deductible donation.

Reproduced with permission from Ben Davison, editor/publisher



Date: September 9, 2006

University of Iowa Hospitals and Clinics

Physicians, Podiatrists, Dentists $100.00
All other allied health professionals $50.00

Register by calling 339-335-8599

Additional information please visit

THMS: 2006 Toronto Hyperbaric Medicine Symposium

2006 Toronto Hyperbaric Medicine Symposium
Date: September 29, 2006
Location: Toronto General Hospital (MaRS building)

THMS Themes:
* Technological Frontiers * Critical Care
* Clinical Chamber Ergonomics * Preconditioning with HBOT
* Osteogenesis * Radiation Injury Managment
* And More...

The THMS is a 1-day symposium that focuses on research level topics. The morning will feature both thematic and pleanry sessions proveded by leaders in hyperbaric medicine. The afternoon will be varied and consist of small group sessions as well as hands-on demos. The opportunity for interaction with faculty is a priority of the meeting.

For More Information, Updates, & Early-Bird Specials: Visit us online at:

Course Director: A. Wayne Evans, MD

Should All Divers be Screened for PFO?

An increased prevalence of brain lesions has been found in divers even in the absence of recognized decompression illness. Permanent neuropsychological changes such as memory disturbances and depression have been found in professional divers, even in those who have never had decompression sickness. The changes are probably the result of intravascular gas bubbles insufficient to cause acute symptoms. A study examined amateur divers with long histories of self-contained underwater breathing apparatus diving by magnetic resonance imaging and compared them with normal controls. Hyperintense lesions of the subcortical cerebral white matter and degenerative changes of the cervical disks were significantly more common in the divers. 27 of 52 divers had a total of 86 focal hyperintensities versus 10 of 50 controls with 14 focal hyperintensities (p < 0.01). [Reul J, Weis J, Jung A, Willmes K, Thron A. Department of Neuroradiology, Technical University, Aachen, Germany.]

In a seminal study, transcranial Doppler ultrasonography detected a right-to-left shunt in all divers with multiple brain lesions. Multiple brain lesions in sport divers were associated with presence of a large patent foramen ovale. This association suggests paradoxical gas embolism as the pathological mechanism. A patent foramen ovale of high haemodynamic relevance seems to be an important risk factor for developing multiple brain lesions in sport divers.[Michael Knauth et al, Department of Neuroradiology University of Heidelberg Klinikum Heidelberg Im Neuenheimer Feld 400 D 69120 Heidelberg Germany, b Department of Neurology, University of Heidelberg, Klinikum Mannheim, Germany, c Department of Biology, University of Frankfurt, Klinikum Frankfurt, Germany]

A foramen ovale no doubt accounted for most of these cases. A comparative investigation regarding brain lesions and the presence of a foramen ovale in sport divers and non-diving controls showed that brain lesions were more common in individuals with a foramen ovale, although divers had more brain lesions than non-divers, irrespective of the presence of a PFO. In a Swiss University and dive club study, the risk for decompression illness events was 4.5-fold greater in divers with patent foramen ovale than in divers without patent foramen ovale (risk ratio, 4.5 [95% CI, 1.2 to 18.0]; P = 0.03). Among divers, 1.23 ± 2.0 and 0.64 ± 1.22 ischemic brain lesions per person (mean ± SD) were detected in those with and those without patent foramen ovale, respectively. Among controls, 0.22 ± 0.44 and 0.12 ± 0.63 lesion per person were detected (P < 0.001 for all groups). Conclusions: Regardless of whether a diver has a patent foramen ovale, diving is associated with ischemic brain lesions. [Schwerzmann et al]

This has led some diving schools to recommend screening for the presence of a PFO for professional divers or avid amateurs. In such divers, PFO closure would make sense. If a non-invasive, inexpensive, valid method for determining the presence or absence of a PFO could be found - would it be protective for decompression illness, or better yet protective for brain lesions in the absence of decompression illness.

There is a study that was done in 2001 in Finland that found that ear oximetry fit the bill for all of these factors. As reported in Stroke. 2001;32:448, "Ear Oximetry: A Noninvasive Method for Detection of Patent Foramen Ovale", the following results were noted:—Dye dilution curves were obtained from 67 patients. Dye dilution correctly diagnosed 35 of the 46 patients who had PFO in TEE and all the 21 patients without PFO. Thus, the sensitivity (95% CI) of the dye dilution method was 76% (61% to 87%) and its specificity 100% (84% to 100%). Ear oximetry was done on 83 patients. Oximetry correctly diagnosed 45 of the 53 patients who had PFO in TEE and all of the 30 patients without PFO. Thus, the sensitivity of ear oximetry was 85% (72% to 93%) and its specificity 100% (88% to 100%). When only the largest shunts were included, oximetry had a sensitivity of 93% (38 of 41).The interrater agreement was excellent ({kappa} value 0.94 for dye dilution and 0.90 for oximetry).

Conclusions—Dye dilution and oximetry are both sensitive and specific methods for the detection of PFO. Oximetry has the following primary advantages over the currently available diagnostic methods: it is noninvasive, safe, and inexpensive and causes no discomfort for the patient. We suggest that oximetry could be used as a first-line screening method for PFO in patients with cryptogenic stroke. Ear oximetry also has potential use in epidemiological studies. [Vesa Karttunen, MD et al from the Department of Neurology (V.K., M.H.) and the Department of Cardiology (M.I., M.N.), Oulu (Finland) University Hospital; and the Department of Cardiology (M.V.), Helsinki (Finland) University Central Hospital. ] Full Text at .

Scientists in Switzerland have also found that those with PFOs more than 9mm in diameter had a much higher risk of DCI. They were up to 13 times more likely to have ended up in a chamber for treatment and five times more likely to have had major DCI than divers without a PFO or divers with a small PFO.

Research by Dr Peter Wilmshurst, a British expert in this field, has confirmed the importance of PFO size. He says: ‘There is no doubt that here, as in most things, size really does matter. The bigger your PFO, the greater your chance of getting bent. But to put this into perspective, only 1.3 per cent of the population have PFOs that are 10mm in diameter or larger and these people suffer between 30 and 40 per cent of all bends.’

Dr. Avi Shupak, Haifa, Israel writes :
I have read with great interest your excellent summary on PFO as a risk factor for DCI and long term neurological effects in divers.

I would like to draw your attention to a recent article published in Mayo Clin Proc 2006;81:602-8 (Petty GW, et al. Population-based study of the relationship between PFO and cerebrovascular ischemic event.). The study results showed that PFO is not an independent risk factor for cryptogenic ischemic stroke or TIA. The data analysis also included separate evaluation of large PFO as a risk factor that reach identical conclusion.

Although the damage mechanism of paradoxical gas emboli (anticipated during a dive) might differ from the pathogenesis of cerebrovascular event by solid emboli, the remarks of the authors about possible methodology flaws in previous studies reporting PFO to be a risk factor for cryptogenic CVA might be of relevance to parallel studies in divers.

Best Regards,

Avi Shupak, MD

Haifa, Israel

We posted this article May 30, 2006 without very much comment. See

See also:
Patent Foramen Ovale

B. Meier and J. E. Lock
Contemporary Management of Patent Foramen Ovale
Circulation, January 7, 2003; 107(1): 5 - 9.
[Full Text] [PDF]


Suunto Dive Computers Recalled After Decompression Hazard

Suunto Dive Computers Recalled After Decompression Hazard

The U.S. Consumer Product Safety Commission in conjunction with Suunto Oy, of Finland, is issuing a voluntary recall for 3,900 Suunto D9 and D6 Model Wristop Dive Computers.

Suunto has found that these dive computers could incorrectly track dive time, which could cause incorrect calculation of decompression requirements, possibly leading to decompression illness.

There have been no incidents or injuries reported but the company still feels the product is unsafe.

The dive computers in question are the D9 and D6 diving instruments which are advanced, gas-switching, multi-mode, decompression dive wristop computers.
The products included are: the D9 model with serial numbers 62102582 and below; and the D6 model with serial numbers 62103693 and below. The serial number is located on the side of the product. The model number is located on the back of the product.

The computers were sold at diving specialty shops nationwide, as well as various Web sites, from September 2004 through June 2006 for about $1,275 for the D9 (without wireless transmitter) and $900 for the D6.

Divers should only use these dive computers with backup instrumentation and should bring the recalled units to the nearest authorized Suunto dealer for a software update to correct the problem. A free battery replacement and pressure testing will be provided as part of the free software update service. All updated products will be marked with an indelible white dot on the back of the unit, or with an engraved "U" near the serial number.

Consumer Contact: For additional information and a list of authorized retailers, visit Suunto's Web site at, call Suunto at (800) 543-9124 between 8 a.m. and 4 p.m. ET Monday through Thursday, and between 8 a.m. and 12 p.m. Friday, or email the firm at

Tuesday, July 18, 2006

More About the Hyperbaric Chamber in Dominica

Since our report about the hyperbaric chamber in Dominica, we have received this press release from Arun Madisetti.

"The long awaited hyperbaric chamber is now installed, tested, and
operational at the Princess Margaret Hospital, Roseau.

A staff comprising of emergency nurses, hospital technicians, and Dive
Instructors have been trained by the manufacturer to operate and man it.
The chamber has been needed for a long time, and through the Ministry of
Tourisms, Ecoutourism Development Program, funded by the European Union, one
was sourced and brought to the island.

The chamber is a Haux Starcom 1500, able to take 4 seated or 2 seated and
one lying patient.

The Dominica Watersports Association anticipates that it would be used for
at worst case scenario 2 cases a year,acting mainly as a safety blanket,
should the unforseen occur.The Watersports Associations standards are
amongst the highest in the region for all watersports. The benefits for
medical applications are obvious.

Hyperbaric medical training was conducted under the auspices of the Undersea
and Hyperbaric Medical Society,by Dr. Julian Eden of the London Diving
Chamber and E-Med., hyperbaric technical training was undertaken by Haux.

Arun Madisetti
Marine Manager
Soufriere Scotts Head Marine Reserve
Dominica Marine Reserves
C/o Fisheries Division
Bay Front Headquarters
Commonwealth Of Dominica
00109-8000, West Indies

tel: (767) 266-5266
fax:(767)448-0140 "

Monday, July 17, 2006

Assessing Fitness to Return to Diving after Decompression Illness

The DMAC in the UK, (The Diving Medical Advisory Committee) has the following 'Guidance' concerning the return to diving of commercial divers who have had decompression illness. These have not been updated since 1994, but appear valid for divers now. The main difference between commercial divers and sport divers is the multiday, multidive aspect of recreational diving and the ability of commercial diving to recompress immediately on the dive boat. These recommended times away from diving differ somewhat for the diving instructor, who comes under commercial regulation by the HSE directive at [Thanks to Dr. John Ross for this information].
* See below for times away.

"The following minimum periods are recommended before returning to diving after decompression illness. The period begins after completion of successful treatment (there are no residual manifestations). It is stressed that these recommendations represent minima and longer lay-offs may be necessary in individual cases.

A. Limb pain, cutaneous (skin rash with severe itching), lymphatic (swelling of tissues) or non-specific (persistent headache, excessive fatigue, loss of appetite, nausea) manifestations only
i) With uncomplicated recovery: 24 hour lay-off
ii) Where there has been a recurrence or relapse requiring further recompression: 7 day layoff

B. Neurological or pulmonary manifestations:
i) Altered sensation involving the limbs only: 7 day layoff
Return to diving only after review by a diving medicine specialist
ii) Other neurological (including audiovestibular) or pulmonary manifestations: 28 day lay-off
Return to diving only after review by a diving medicine specialist

C. After an incident of pulmonary barotrauma resulting in a pneumothorax or mediastinal/subcutaneous emphysema, the diver should be assessed by a diving medicine specialist. Return to diving may be permitted, but not normally until at least 28 days following complete recovery.
In cases where there are significant residual neurological manifestations, even after repeated treatment, the diver should normally be considered unfit to dive. Return to diving should only be permitted if sanctioned by a diving medicine specialist.

Divers Alert Network has a question and answer FAQ about returning to diving after decompression illness. This link also reproduces the recommendations of the US Navy.

Lippmann and Mitchell, in the latest edition of their book, "Deeper into Diving", state that most resolved cases of decompression illness should wait at least one month before returning to diving. They feel that divers who have had CAGE (cerebral arterial gas embolism) from pulmonary barotrauma should not return to diving due to the probability of lung scarring and elevated risk of subsequent recurrence of DCI.

Others feel that return to diving depends upon the cause of the barotrauma and allow resumption of diving after three months and no evidence of air trapping upon spiral CT scan study of the lungs.

For example, if a diver has a cause for the pulmonary barotrauma, such as an emergency ascent or other breath holding rise from depth - then a resumption of diving in three months can be entertained after ascertaining that there is no air trapping as shown by functional tests (helium loop), chest x-ray or a CT scan.

*Times away from diving

13. The recommended minimum times away from diving after successful treatment with no sequelae are:
---Uncomplicated recovery 24 hours
---Recurrence/relapse requiring further recompression 7 days

---Altered sensation in limbs only--- 7 days
---Audiovestibular, motor---- 28 days
Pulmonary decompression Illness--- 28 days
14. Because of the nature of their diving patterns and profiles and the lack of supervision, it is recommended that the time away from diving for those diving at work in the recreational sector should be longer. The Diver’s Alert Network (DAN) Website recommendations on diving layoff times for recreational divers are found at:

Saturday, July 15, 2006

Driving to Higher Altitude After Diving

Driving to higher altitude after diving.

Several years ago I ran across this explanation of the physiology of driving to higher altitudes after diving and found it well written. Author unknown.

"So here's my understanding of the physiology: Obviously, nobody worries about the altitude of their room in that high-rise Honolulu hotel. So it's simply incorrect to say, "Never go to higher altitude after a dive." The issue is "How much altitude?" and "How do you adjust your dive plan for anticipated changes of altitude after the dive?" Increasing altitude DOES increase the risk of decompression illness, but this risk is manageable by appropriate dive planning. The atmospheric pressure at 5000 feet (my home in Alpine Utah) is approximately 640 mm Mercury. This compares to 760 mm Hg at sea level. (The difference is the equivalent of about 5 feet of water. So when diving at altitude, you become nitrogen-saturated a little less quickly. This isn't a big factor, and the deeper you dive, the less significant it becomes.) When you emerge from the water, there's less pressure to hold nitrogen in solution in your blood. Example: When diving at, say, 65 feet depth at 5000 feet of altitude, you'd absorb nitrogen 5% slower. But once you emerge, there's 15% less pressure holding the absorbed nitrogen in solution.

The pressure holding the nitrogen in solution is the critical factor in preventing decompression illness. So divers at altitude adjust their dive plan by substituting DEEPER depths for the actual depths they've dived. They assume they'll absorb nitrogen faster (they don't really). But when those numbers are plugged into the "sea level" dive table, it balances out. In other words, at 5000 feet, you assume you have 15% more nitrogen rather than 15% less pressure holding the nitrogen in solution, and it balances out. That way, you don't need a full dive table for every altitude. So how about diving at low altitude, then driving to higher altitude later? Well, let's assume we're ALREADY diving at that altitude. It poses no significant risk to travel to altitude if you've planned your dive AS THOUGH YOU'LL BE EMERGING FROM THE WATER AT THAT ALTITUDE. Got that concept? If you compute your safe level of nitrogen saturation as if you'll be emerging from the water at 5000 feet, how can it be more dangerous emerge from the water at sea level then drive to 5000 feet? Seems to me, the time it takes to drive to that altitude is one hell of a safety stop.

So my advice for diving, then driving to altitude is:
(1) Switch from computer to dive tables. The dive tables, properly used, will be more conservative. And they allow you to adjust for altitude.
(2) Use an altitude-adjusted depth in your dive table. Specifically, you should use the highest altitude you'll reach within 24 hours of the dive AS THE ALTITUDE OF THE DIVE.
(3) Substitute this "drive-altitude-adjusted depth" for the actual depth of the dive in your dive table.
(4) PLAN YOUR DIVE, AND DIVE YOUR PLAN. For example, if I'm diving at 6000 feet elevation, but driving home by way of a mountain pass at 9,500 feet, I use 10,000 feet as the depth of the dive (instead of 6000). There is a table for altitude-adjusted depths at

More information about this from Jim Grier in an article he wrote for ScubaDiving .com "Tips".

See also:
1. history of decompression safety and dive tables
2002 Flying After Diving DEMA Flying After Diving: History, Research & Guidelines Richard Vann ... 1st Report Cabin altitude 8-10,000 ft Pilot ... 4 hrs after diving to 30 fsw Flight

2. Diving Physics
Diving Physics Register || Site Map || SiteSearch ... Email || Translate || Home Diving Physics and Physiology In order ... be encountered while diving, one must thoroughly understand

3. Flying After Diving-
fly too soon after diving, gives parameters for time limits and ... flying. Flying after Diving* This website is written and ... Campbell, MD, FACS 'Diving Medicine' The question is often

4. Microsoft Word - 3CA4866A-1252-C19C.doc
FALL PARACHUTING AFTER DIVING PROJECT REPORT Funded by U ... when flying follows diving. Male volunteers completed simulated 60 ft/60 min dives followed by three hours at 25,000 ft to

5. Diving At Altitude
to correct for diving at altitude DIVING MEDICINE ONLINE Diving At Altitude (A simplified method to obtain ... Ware, PhD [CAUTION: Diving at altitude requires special training which

6. Parameters for Flying After Diving
for Flying After Diving Flying after Diving* This website is written and ... Campbell, MD, FACS 'Diving Medicine'The question is often ... to fly after diving"? The answer to the question

7. Flying After Diving
take place with diving and flying HOME > Here ... Flying and Altitude Parameters for Flying After Diving Diving After Flying? DAN has ... Flying After Diving Presentation, Dr. Richard

Friday, July 14, 2006

Abandoned Divers, What to do, How to Prevent

The Boat

* Check out the boat and boat captain before diving
* Ask questions about rescue action plans
* Ask about the history of the motor
* Ask about the credentials of the crew
* Ask about the system for counting heads (Names!)
* Find out if the boat has a functioning radio
o Request to see and hear it function
o Ask who they call for assistance
* Be alert to location of the nearest land

Important! Don't be put off by an officious captain! Your life may be at stake. If the captain doesn't want to cooperate - ask your dive leader to intervene or get off the boat.

The Dive

* If a drift dive, listen carefully for instructions, stay with the group
* Check for current, tide and wind conditions; imagine yourself out of sight of the boat
* Always start your dive by swimming upcurrent after orienting yourself
* Develop navigational skills. See

Equipment possibly helpful

* Inflatable Sausage
* Reflector
* Whistle or other noise maker
* Slate
* Line

Hazards of being left behind

* Dehydration and thirst
* Hypothermia
* Severe sunburn and immersion injury
* Marine animal injury
* Drowning

Things to do

* Inflate BC
* Drop weights, preserving belt
* Inflate sausage
* Flash reflector (Someone might see it, even though you can't see them)
* Blow whistle
* Write time, approximate location and speed of current on your slate
* If you swim, swim diagonally with the current toward any known dry land.
* Stay with others involved. Use a tie up method using empty weight belt or other straps. This gives a larger target for searchers.
* Remember that there will be rescue attempts and searchers.

'Seven Steps to Survival'

Survival at sea depends on the recognition that you are in danger of losing your life. There are commonly described "seven steps" to survival that may make a difference in the outcome of some rather terrible situations. Even an accident fairly close inshore in cold water can quickly lead to hypothermia and drowning. The seven steps to survival are: recognition, inventory, shelter, water, food, signals and play. Of course, flotation is a prerequisite for any survival after only a short time in the water. Other factors come into play, the most important of which is unmeasurable, "the will to live".

The seven steps to survival include recognizing that you are in peril and realizing that what you are wearing constitutes a form of shelter. Use signals in the form of mirrors, flares, colored objects or waving arms, suits or objects about to attract attention. Finally, "play" comes into action as you have memories, fantasies, prayer, tell jokes and get rid of your anger.

SCUBA diving for individuals with disabilities

We get fairly frequent requests for information concerning diving with various disabling conditions and have generally applied the knowledge known to exist for all divers to the limitations of the particular disability involved. This has in most cases been satisfactory but occasionally we run into a wall of lack of pertinent information, such as the effect of pressure on electronic implants and pumps. Cheng and Diamond published a review of potential problems that they recognized as being important to divers with disabilities in the American Journal of Physical Medicine and Rehabilitation in May of 2005 and the article is paraphrased below.

Cheng J, Diamond M.
SCUBA diving for individuals with disabilities.
Am J Phys Med Rehabil. 2005 May;84(5):369-75. Review.

Potential Medical Problems in Divers
with Disabilities

Osteoporosis and Fractures
Immobilization and paralysis can place some people with disabilities are at risk for osteoporosis.8,9 Divers at risk for pathologic fractures should seek dive boats with access platforms near water level for easier transfers in and out of the water. It would be rare for dive boats to have lifts that are commonly found in accessible pools. Many neurologic disorders have loss of sensation and fractures may go unrecognized. Unexplained lower limb swelling or redness should be evaluated for possible pathologic fracture.

Medical Implants
Questions are posed concerning the integrity of medical appliances when exposed to the increased barometric pressures associated with SCUBA diving. Many individuals with disabilities such as spina bifida have connections between the brain anf the abdominal cavity (ventriculoperitoneal shunts) for the treatment of hydrocephalus (excessive fluid on the brain). Huang et al.10 subjected four ventriculoperitoneal shunts to one and four atmosphere absolute in a hyperbaric chamber and found that all shunts performed according to manufacturers’ specifications. They reasoned that any increase in pressure will compress all fluid-filled compartments. Therefore, there would be no significant change in gradient between intracranial and intraperitoneal pressures. Preliminary studies have been carried out for cochlear implants in a hyperbaric chamber, illustrating that the implantable components of various cochlear mplants can withstand pressures of up to six atmospheres without damage or failure of critical seals.11

Intrathecal baclofen pumps are increasingly being utilized in the management of spasticity and dystonia. Akman et al.12 described a case of retrograde leakage of cerebrospinal fluid (CSF) into the infusion pump reservoir of an intrathecal baclofen pump (Medtronic SynchroMed, Medtronic, Minneapolis, MN) during hyperbaric oxygen therapy. Medtronic does not recommend exposing their intrathecal baclofen pumps to pressures of 2.0 atmospheres absolute (SynchroMed II Technical Manual, Medtronic).

Thermal Regulation
Some disabled have an inability to maintain heat regulation. For those individuals with this problem, diving should be undertaken in warm water regions and cold protection wetsuits should be utilized. Deeper diving will cause increased compression of the air in neoprene wetsuits. Because a large component of the insulating quality of wetsuits is provided by the air trapped in the material, compression of these garments will decrease their insulating capabilities.13 When diving to greater depths, the need for increased thermal protection should be anticipated due to the compression of neoprene and the much colder water. Peripheral vasoconstriction, as an adaptation to minimize the strain caused by loss of body heat, may compromise circulation to the limbs and may need to be minimized.13 This vasoconstriction may decrease already decreased circulation to the limbs of some individuals with paraplegia. For example, Boot et al.14 found that individuals with spina bifida and spinal cord injury have peripheral arterial vasculature that was of smaller diameter, lower flow, and higher shear stress when compared with controls. These changes may compromise optimal regulation of the peripheral vasculature. For individuals with spinal cord injury at the neurologic level of T6 and above, exposure to cold water may increase sympathetic nervous system activity, inducing or exacerbating autonomic dysreflexia. 15 Development of autonomic dysreflexia at greater depths may become life-threatening. The need for slow ascent and safety stops may prevent the individual from receiving needed medical care quickly. Individuals with spinal cord injury who are at risk for autonomic dysreflexia should be monitored for common symptoms such as headache, vision changes, and flushing.

Atrophy and Hypotrophy
It should be noted that due to atrophy and hypotrophy of the lower limbs associated with paraplegia and tetraplegia and other disorders, regular wetsuits may not fit properly and custom wetsuits may be necessary to ensure proper fit and optimal heat retention. Because of decreased muscle mass in the lower limbs there may be increased buoyancy and ankle weights may be required to gain neutral buoyancy in the lower limbs. Due to increased buoyancy, this may be worsened when a full wetsuit is worn. 7

Cardiovascular Issues
Paraplegics and some amputees must rely on the upper limbs for propulsion and there are some physiologic factors that need to be considered when the upper limbs alone are used for propulsion. Activities performed with the upper limbs compared with the lower limbs require higher myocardial oxygen consumption at the same total oxygen consumption inducing more stress by upper limb propulsion underwater. Cardiac disorders are common with many neurologic and muscular conditions such as the muscular dystrophies/myopathies, Friedreich’s ataxia, and many syndromes. The shift of blood into the central circulation resulting from water immersion may aggravate congestive heart failure.17 There is also increased myocardial demand in diving due to increased exertion.13 In addition, immersion in cold water can also cause a significant increase in metabolic rate.15 Given these potential stresses on the cardiovascular system during diving, cardiac function should be evaluated carefully in those individuals who have documented cardiac disorders or conditions that predispose them to cardiac pathology. The use of webbed gloves can help facilitate propulsion with the upper limbs and disabled divers may also opt for the use of motorized propulsion devices that are available from several manufacturers and utilized by many nondisabled divers as well.

Venous Stasis
Levey et al. investigated the relationship of spina bifida and deep venous thrombosis and speculated that individuals with spina bifida may be at higher risk due to venous insufficiency and lower limb paresis.18 There is no direct evidence that SCUBA diving increases the risk of deep vein thrombosis. But, given the increase in prevalence of deep vein thrombosis in individuals with spina bifida, it would be prudent to monitor closely for signs and symptoms such as lower limb swelling and dyspnea that may suggest deep vein thrombosis or pulmonary embolus.

Decompression Sickness
The brain and spinal cord contain myelin, which is very susceptible to excess nitrogen supersaturation after ascent.17 Symptoms of air embolism affecting the brain or spinal cord include unconsciousness with stroke-like symptoms, paralysis, seizures, bowel/bladder dysfunction, sensory abnormalities, fatigue, personality change, poor concentration, irritability, and changes in vision.17 The cortical gray matter is more efficient at releasing nitrogen compared with the spinal cord.1,19 Therefore, the spinal cord is at particular risk for decompression sickness. Venous bubbles can cause thrombosis of the venous plexus surrounding the spinal cord, resulting in venous stasis and spinal cord ischemia.1 However, there is no direct evidence that individuals with spinal cord dysfunction or cortical neurologic disorders are at greater risk of decompression sickness of the brain or spinal cord. Boot et al.14 found that individuals with spina bifida had common femoral arteries that were smaller, with decreased blood flow, compared with normal controls. It is unknown if these arterial characteristics increase the risk of decompression sickness and there are currently no studies investigating the appropriateness of the use of current dive tables by the disabled population. Individuals with disabilities may be at increased risk in the context of decompression sickness because neurologic impairment caused by the decompression sickness can be confused with or masked by the neurologic signs and symptoms associated with the divers’ disease processes. Therefore, it is very important for the disabled diver and his or her dive companions to be familiar the signs and symptoms of decompression sickness and be able to contrast them with the disabled individual’s baseline state.

Many individuals with disabilities have seizure disorders related to their disease processes. Any seizure underwater would result in severe drowning risk and would also be a danger to that diver’s partner. Therefore, seizure disorder requiring ongoing medical management is a strict contraindication to SCUBA diving.17,20 Some certifying agencies, however, will allow divers who have been seizure-free without medications for 5 yrs to participate in their diving programs.

Pneumothorax can be spontaneous or result from trauma. Spontaneous pneumothorax can be associated with structural abnormalities and lung disease.21 It is a strict contraindication for SCUBA diving because the underlying cause may still be present at the time of diving.20 Many individuals who have disabilities resulting from traumatic events have had pneumothoraces. Traumatic pneumothorax, however, is not a contraindication provided that the injury is well healed.

Latex allergy is rare in the general population, with a prevalence of 1%.22 However, it is a concern for individuals with spina bifida and other disorders.22–25 Latex allergy is very common in these populations, with up to 60% of individuals with spina bifida having allergies to latex.25 It is an immunoglobulin E–mediated hypersensitivity reaction to natural rubber latex that can result in urticaria, rhinitis, bronchospasm, and anaphylaxis.23 Bernardini et al.25 found that 25% of subjects with spina bifida had latex sensitization, and only 33% of those individuals have had clinical reactions to latex. Although severe reactions are rare, such reactions at greater depths would present a life-threatening event. Therefore, previous screening is important. Individuals at risk for latex allergies, especially people with spina bifida, may wish to consult an allergist for skin prick or serum latex-specific immunoglobulin E antibody testing before considering SCUBA diving. Those individuals who are at risk may wish to have antihistamines and intramuscular epinephrine available in case of a serious reaction. It may also be prudent to contact the manufacturers of the equipment to be used to determine the precise material content to further decrease the risk. The majority of modern diving masks and snorkels are made from silicone. Also, there is usually no natural latex in neoprene wetsuits. However, certain seals and tubing may contain latex, as may seams in certain wetsuits. Latex seals are much more common in dry suits in which water-tight seals are required. Wetsuits manufactured from neoprene rarely have latex seals. Air tubing may contain natural latex, but the latex is usually vulcanized with other materials and therefore would not likely cause a hypersensitivity reaction. However, it may be best to contact individual manufacturers to confirm the latex content in their air hoses. Alternatively, silicone tubing can be utilized to further reduce the risk.

Many conditions resulting in paraplegia are also associated with sensory deficits. Because of insensate skin, these individuals are at risk for developing pressure ulcers and injuries from trauma. Muscle atrophy also results in decreased protection normally afforded by muscle mass and therefore increases the risk of pressure ulcers. In addition, these individuals are at risk for unrecognized burns from sun exposure. Wetsuits may provide a certain level of protection from skin injury. During the dive, they may protect from abrasions and lacerations while preventing sunburn while on the surface.

Bladder Management
Water immersion and cold exposure have been found to cause diuresis by increasing plasma volume and increasing the release of factors such as atrial natriuretic peptide.26,27 Changes in urine production can become a factor in individuals requiring catheterization because of a neurogenic bladder. Individuals whose bladder programs include clean intermittent catheterization may be required to catheterize more often to address the increased diuresis. This may be difficult given the limited space of a dive boat. It would be an important consideration to identify dive boats that have private spaces available for bladder management and a means of washing hands to maintain the aseptic nature of the procedure. Individuals who are on clean intermittent catheterization programs may regularly limit their intake of fluids to reduce the frequency of catheterizations throughout the day. While SCUBA diving, the sources of fluid loss as previously described and those associated with increased exertion and ambient temperature may predispose the diver to dehydration. In addition, wetsuits provide significant thermal protection while in the water. However, prolonged wetsuit wearing may result in hyperthermia, increased sweat production, and dehydration. 13 Therefore, careful monitoring of fluid intake and output balance and monitoring for symptoms of dehydration are very important in this population. Also, bladder distention can be of particular concern for spinal cord–injured patients with a neurologic level above T6 who are at risk for autonomic dysreflexia.

Ear Barotrauma
Problems associated with middle-ear spaces and paranasal sinuses are the largest source of morbidity among SCUBA divers.20 As a diver descends, external pressure increases and pushes on the tympanic membrane. This pressure needs to be equalized in the middle ear through the oropharynx via the eustachian tube.17 Equalization involves forcefully exhaling against closed (pinched off) nares. Inability to properly equalize will cause barotrauma and may result in pain, acute hemorrhagic otitis media, or tympanic membrane rupture. 17,20,28 Therefore, before diving, each individual should be evaluated for the ability to perform this maneuver independently or with the assistance of another diver.

Asthma affects 6–7% of the general population in the United States, often with childhood onset.17 Some have supported that any history of asthma is a strict contraindication.20 However, asthma varies greatly in severity and in its triggers across individuals. 3 Bove17 states that individuals with mild asthma should not be prohibited from diving. Neuman et al.3 suggests that individuals with normal airway function at rest with little airway reactivity to exercise or cold air inhalation may have risks of pulmonary barotrauma similar to nonasthmatic individuals. However, air-trapping at depth while breathing compressed air in individuals with asthma can lead to serious pulmonary barotrauma. 3,29 Therefore, subjects with a history of asthma should be screened carefully. Additional research may be helpful to better describe the risks for different asthma severities and triggers as opposed to using a history of asthma as a strict contraindication for diving.

Certifying bodies for recreational SCUBA diving such as the Professional Association of Diving Instructors and the National Association of Underwater Instructors have requirements for swimming and fitness. For example, Professional Association of Diving Instructors requires that an individual be able to tread water for 10 mins and swim for 200 meters independently, even though these skills are rarely needed in SCUBA diving. The authors advocate that for full certification, individuals with disabilities should be held to the same requirements and standards as their able-bodied peers. This is to ensure the highest level of safety for the disabled diver. In addition, an important component of SCUBA certification is the ability to perform skills necessary to assist a dive partner. Any disabled individual who is to be a candidate for full certification should be able to carry out these responsibilities. The Handicapped SCUBA Association has established a hierarchical certification structure based on each diver’s abilities. This system allows individuals with disabilities to participate in SCUBA diving at different levels of independence based on their level of function (Table 1).7

SCUBA diving is an adventurous sport that allows participants to explore a diverse, exciting marine environment. Guidelines have been established by SCUBA certification organizations to minimize injury and injuries often occur when these guidelines are violated. However, some individuals may experience injury even when diving conservatively. Mortality rates in recreational SCUBA diving are estimated to be one to nine in 100,000 divers.1,2,30 The authors advocate that SCUBA diving be made available to as many interested individuals as possible. It can be a great source of self discovery and a means of building confidence and independence. However, individuals with disabilities present with many medical conditions that need to be considered carefully by their physicians before certifying them as fit to dive. Recognizing and addressing risk factors can help to limit morbidity and mortality. Additional research into how the unique anatomy and physiology of individuals with disabilities interact with a hyperbaric, marine environment would help to better refine guidelines and allow safer diving in the least restrictive framework.

TABLE 1 Levels of certification available from the Handicapped SCUBA Association
Level A
Able to provide equal assistance to a fellow diver in case of an emergency. Qualified to dive with another certified diver, including a level A diver.

Level B
Able to care for self in case of an emergency but cannot provide a fellow diver equal assistance in case of an emergency. Qualified to dive with two certified divers who may be level A.

Level C
Able to safely use SCUBA underwater but unable to effectively care for self or a fellow diver in case of an emergency. Must dive with two certified divers, one of whom has been trained by a nationally recognized diver training agency in diver rescue. In most cases, this would be an instructor, assistant instructor, or dive master.

1. DeGorordo A, Vallejo-Manzur F, Chanin K, et al: Diving emergencies. Resuscitation 2003;59:171–80
2. Spira A: Diving and marine medicine review part II: Diving diseases. J Travel Med 1999;6:180–98
3. Neuman TS, Bove AA, O’Connor RD, et al: Asthma and diving. Ann Allergy 1994;73:344–50
4. Pelletier JP: Recognizing sport diving injuries. Dimens Crit Care Nurs 2002;21:26–7
5. Frankel H: Aqualung diving for the paralysed. Paraplegia 1975;13:128–32
6. Williamson JA, McDonald FW, Galligan EA, et al: Selection and training of disabled persons for scuba-diving: Medical and psychological aspects. Med J Aust 1984;141:414–8
7. Madorsky JG, Madorsky AG: Scuba diving: Taking the wheelchair out of wheelchair sports. Arch Phys Med Rehabil 1988;69(3 pt 1):215–8
8. Chan YY, Bishop NJ: Clinical management of childhood osteoporosis. Int J Clin Pract 2002;56:280–6
9. Apkon SD: Osteoporosis in children who have disabilities. Phys Med Rehabil Clin N Am 2002;13:839–55
10. Huang ET, Hardy KR, Stubbs JM, et al: Ventriculo-peritoneal shunt performance under hyperbaric conditions. Undersea Hyperb Med 2000;27:191–4
11. Backous DD, Dunford RG, Segel P, et al: Effects of hyperbaric exposure on the integrity of the internal components of commercially available cochlear implant systems. Otol Neurotol 2002;23:463–7; discussion, 467
12. Akman MN, Loubser PG, Fife CE, et al: Hyperbaric oxygen therapy: Implications for spinal cord injury patients with intrathecal baclofen infusion pumps. Case report. Paraplegia 1994;32:281–4
13. Doubt TJ: Cardiovascular and thermal responses to SCUBA diving. Med Sci Sports Exerc 1996;28:581–6
14. Boot CR, van Langen H, Hopman MT: Arterial vascular properties in individuals with spina bifida. Spinal Cord 2003;41:242–6
15. Sramek P, Simeckova M, Jansky L, et al: Human physiological responses to immersion into water of different temperatures. Eur J Appl Physiol 2000;81:436–42
16. Braddom R: Physical Medicine and Rehabilitation, ed 2. Philadelphia, WB Saunders, 2000
17. Bove AA: Medical aspects of sport diving. Med Sci Sports Exerc 1996;28:591–5
18. Levey EB, Kinsman KF, Kinsman SL: Deep venous thrombosis in individuals with spina bifida. Eur J Pediatr Surg 2002;12(suppl 1):S35–6
19. Barratt DM, Harch PG, Van Meter K: Decompression illness in divers: A review of the literature. Neurologist 2002;8: 186–202
20. Dembert ML, Keith JF III: Evaluating the potential pediatric scuba diver. Am J Dis Child 1986;140:1135–41
21. Noppen M: Management of primary spontaneous pneumothorax. Curr Opin Pulm Med 2003;9:272–5
22. Turjanmaa K, Makinen-Kiljunen S: Latex allergy: Prevalence, risk factors, and cross-reactivity. Methods 2002;27: 10–4
23. Mazon A, Nieto A, Linana JJ, et al: Latex sensitization in children with spina bifida: Follow-up comparative study after two years. Ann Allergy Asthma Immunol 2000;84: 207–10
24. Hochleitner BW, Menardi G, Haussler B, et al: Spina bifida as an independent risk factor for sensitization to latex. J Urol 2001;166:2370 –3; discussion, 2373–4
25. Bernardini R, Novembre E, Lombardi E, et al: Risk factors for latex allergy in patients with spina bifida and latex sensitization. Clin Exp Allergy 1999;29:681–6
26. Hope A, Aanderud L, Aakvaag A: Dehydration and body fluid-regulating hormones during sweating in warm (38 degrees C) fresh- and seawater immersion. J Appl Physiol 2001;91:1529–34
27. Nakamitsu S, Sagawa S, Miki K, et al: Effect of water temperature on diuresis-natriuresis: AVP, ANP, and urodilatin during immersion in men. J Appl Physiol 1994;77: 1919–25
28. Newton HB: Neurologic complications of scuba diving. Am Fam Physician 2001;63:2211–8
29. Orlowski JP: Adolescent drownings: Swimming, boating, diving, and scuba accidents. Pediatr Ann 1988;17:125– 8, 131–2
30. Morgan WP: Anxiety and panic

Handicapped Scuba Association, Israel

HSA Israel Announced
Dr. Nathan Cohen To Lead HSA in Israel and the surrounding region.

Who could have guessed that behind a tall white fence in a serene residential neighborhood not far from Tel Aviv, history was in the making: the creation of the Handicapped Scuba Association, Israel.
It all began with Dr. Natan Cohen, sponsor of a whirlwind week of HSA training: a Course Director Training Course (CDTC) followed by an Instructor Training Course (ITC) held from November 28 through December 4, 2005.
Since then the on-going process of formalizing the structure of HSA Israel continues to establish its presence under the leadership of Dr. Cohen, President of HSA Israel. The rigors of leadership, however, don’t faze Natan who serves as Deputy Director of Hillel Yaffe Medical Center and Founder of the Child Development Center, an extensive and impressive facility within the hospital.
Dr. Cohen refers to himself as a “Developmental Pediatrician,” meaning he specializes in child development. With that in mind, Natan contacted HSA International, curious to know how scuba diving might benefit young people who are cognitively impaired. He made up his mind and organized the first HSA Course Director Training Course (CDTC) in Israel. The CDTC requires 3 days of intense lectures that train the Course Director candidates how to use the manuals, lectures and water work to develop empathy and instructor teaching skills in their future HSA ITCs.
For each of 3 evenings, the 4 HSA Course Director candidates, including Natan, met in the Cohen’s’ home for highly verbal, even thought-provoking interactions between Gatacre and themselves that lasted long into the night. Natan’s wife, Nurit, graciously provided a tantalizing array of refreshments with which to fuel the active minds of the candidates.
Following their certification exams on the last night of the CDTC, few hours remained for sleep before the ITC they were about to teach was to begin in Eilat many miles south across the starkly beautiful Negev Desert.
All young Israeli men and women serve in the military so there was no mention of fatigue as the Course Director convoy arrived in Eilat countless hours later and immediately launched into Day 1 of the intensive 3-day HSA Instructor Training Course.
Each of the new Course Directors (Dov Bensman, Larry Tenenbaum, Sani Sanilevich and Dr. Natan Cohen) would co-teach the ITC to 8 underwater professionals at Meduza Israeli Sea Center. There on the Bay of Eilat with its calm, shimmering waters, a narrow curve of beach separated the fringe of shoreline from Meduza, operated by Sani and chosen as the host facility for HSA Israel’s debut Instructor Training Course.
It’s easy to see why. As a dive center Meduza has it all, from Nitrox and Tech diving to wreck and cave diving. The Center is replete with an on-site gear shop, a tropical-style snack bar, even its own floating pier.
Not only does Meduza have it all, Sani prides himself in making his Sea Center unique by making it wheelchair accessible. Now Meduza can add one more dive training specialty: training and certifying divers with physical as well as cognitive disabilities.
David Ederi, a Senior Dive Instructor at Meduza for over 3 years, is also the Center’s Web Master.
     “Before we even thought about doing the HSA Course I went to your web site and saw that many diving agencies recognize you,” David observed. “The first time I saw handicapped divers going into the water, I thought that can’t be happening,” he exclaimed, “I mean, for a person who cannot walk to strap himself onto scuba gear and GO...what’s going on there!”
When the HSA Instructor Course appeared on Meduza’s schedule, David signed up.
     “I thought the HSA Instructor’s Course would be a good experience for me,” he reasoned, “it’s a great satisfaction for myself and a great satisfaction for the handicapped diver. That was what motivated me to take the Course. And it was a very insightful much information I didn’t even know existed.”
David is with good company: he’s one of 2,400 HSA Instructors in 46 countries throughout the world whose integrity and sensitivity have transformed the lives of handicapped people eager for safe adventures to enrich their memories.
The Handicapped Scuba Association is an international, independent training and certifying agency with over 4,000 members. HSA Founder and President Jim Gatacre warmly calls them “our army of good guys” as the HSA celebrates its 27th year as the world-wide authority for handicapped diving.
Contacts: Dr. Natan Cohen  

DVD from GUE About Decompression Illness

Like to get your information on a DVD? Tony Rue with GUE sends us this information about Decompression Illness:

"You might be interested in the latest diver education DVD from Global
Underwater Explorers. "The Mysterious Malady: Toward an Understanding
of Decompression Injuries" is a series of interviews with the leading
researchers from Duke's Center for Hyperbaric Medicine, DAN, the
NEDU, and GUE. The program is general enough to appeal to the
recreational diver interested in learning more about what happens to
the body during a dive, yet also has enough information to hold the
interest of the most advanced of technical divers.

From the website: "Decompression techniques are skills to be
cultivated as you progress through dive training, yet this experience
is best framed by a solid understanding of the nature of
decompression and its associated injuries. Global Underwater
Explorers is pleased to present the first in a series of educational
DVD's designed to greatly expand one's knowledge of decompression and
its associated maladies. This DVD emphasizes an overview of
fundamental decompression concepts and the injuries associated with
decompression stress."

Anthony Rue "

More about Decompression Illness at

Study Advises Smoking Cessation in Divers

In an article in the journal Chest titled "Decline of FEV1 in Scuba Divers", a study is reported by Tetzlaff et al that puts to rest the supposition that prolonged diving causes lung problems.
(Kay Tetzlaff, MD; Jens Theysohn, MD; Caroline Stahl; Sabine Schlegel, PhD; Andreas Koch, MD and Claus M. Muth, MD)
Abstract of the article
Correspondence to: Kay Tetzlaff, MD, Medical Clinic and Polyclinic, Department of Sports Medicine, University of Tuebingen Silcherstrasse 5, 72076 Tübingen, Germany; e-mail:

Study objectives: Obstructive changes in lung function have been reported with cumulative scuba diving exposure. The aim of this study was to investigate the decline in FEV1 in scuba divers over time.

Design: Prospective controlled cohort study.

Setting: German Naval Medical Institute.

Patients: Four hundred sixty-eight healthy, male, military scuba divers and 122 submariners (control subjects) were entered.

Measurements and results: Pulmonary function tests were performed in all subjects on at least three occasions with a minimum interval of 1 year between first and last measurement. The decline in FEV1 was investigated fitting a general linear model to FEV1 across time with a factorial main-effects model for slopes and intercepts with respect to the factors group, smoking status, and baseline FEV1. Mean baseline age of all subjects was 32 years (SD, 9.1), and mean body mass index was 24.7 kg/m2 (SD, 2.4). Subjects were followed up for 5 years (range, 1 to 9 years) on average. Baseline FEV1 exceeded the predicted values in both divers and nondiving control subjects. There was no significant difference in the decline of FEV1 between divers and control subjects. Over time, FEV1 declined more rapidly in smokers than in nonsmokers (p = 0.0064) and declined more rapidly also in subjects with a baseline FEV1 above average compared to subjects below average (p < 0.0001). The annual decline of FEV1 peaked in smoking divers who had a high FEV1 at baseline.

Conclusions: The data indicate that scuba diving is not associated with an accelerated decline in FEV1. Combined exposure to diving and smoking contributes to the fall of FEV1; therefore, smoking cessation is advised for divers.

Full text of the article.

Thanks to Dr. Howard Hommler who sent us the article.

Related links on Scubadoc's Diving Medicine Online
'Smoking and Diving'

Cigarette smoking and decompression illness severity: a retrospective study in
recreational divers.

Should Divers Smoke and vice versa

Thursday, July 13, 2006

Pearls of Diving Wisdom: Great Lakes Chapter --- Undersea and Hyperbaric Medical Society

Great Lakes Chapter --- Undersea and Hyperbaric Medical Society
Pearls of Diving Wisdom
See Poster at

Partial list of topics:
Police Diving in Ontario
Diving for a Living
PFO’s (Patent Foramen Ovale) & the Bends
Cold Water Diving
Diabetes & Diving
Children & Diving - How Safe?

Saturday Oct. 21 , 2006

Where Diving and Medicine Meet
We have outstanding speakers, interesting topics, our traditional Myths of Diving Panel and opportunities to make new friends in the diving and diving medical community. Lunch is provided, with refreshments after the meeting.

This is for you---
Recreational and Tech Divers
Professional Divers
Dive Masters & Instructors
Diving & Hyperbaric Professionals

For info & to register
Contact Ron Nishi

0800 Register & Coffee
0830 to 1730 Symposium

$50.00 Cdn / $45.00 US before Oct. 6
$65.00 Cdn / $55.00 US after Oct. 6

Again this year, we are in Burlington at the Canada Centre for Inland Waters.

Wednesday, July 12, 2006

Medical Program in Israel


Pascack Valley Hospital , Westwood, NJ
5th Annual Medical Study Program in Israel
November 8-19, 2006

Subjects include:
Medical Aspects of Scuba Diving
Hyperbaric Medicine

Medical Response to Terrorism
Medical Advances

Itinerary includes Tel Aviv, Beer Sheva, Eilat, Dead Sea, Jerusalem
25-27 CME Category 1 credits

Touring (Including Petra), Scuba Diving Guide, Bus and Driver and Hotels approx $2800

Continental Flights from Newark Airport separate

Contact: William L. Cantor, MD
219 Old Hook Road
Westwood, NJ 07675
Fax: 201-358-6686

Note: Despite the chaos in Israel now, Dr. Cantor writes and tells us that he still plans to go.


Tuesday, July 11, 2006

Upcoming DAN Events

» Trainer Workshops & Instructor Update (7/25/06)
» DAN 57th Diving & Hyperbaric Medicine Course (8/3/06-8/5/06)
» Instructor Trainer Workshop (8/11/06-8/13/06)
» Duke/DAN DMT Course (9/10/06-9/15/06)
» Instructor Trainer Workshop (10/6/06-10/8/06)

More Events
Plan your meetings, courses and events on into 2007.

DCS Support Group started on Yahoo! Groups

Here is a letter from a Leila Cara, a PADI dive instructor, about a DCS support group that she has started on Yahoo! Groups. I've not seen any such thing before but think that it might serve a good purpose for some people. Care must be taken to prevent it's derogation by people who might use it for venting anger. I will watch it with great interest.

I have started a DCS support group to help those recovering from DCS. I would like to alert the diving medical community of this new group. I started it because of a DCS incident 1 year ago and realized there is little support after leaving the hospital. I would love for you, or anyone to visit.

Please spread the word and post wherever suitable.
Thank you again,

Visit me at

New books and classes to fix pain and improve health - Dr. Jolie Bookspan

Next workshop to Fix Your Own Back and Neck Pain: Snowmass Colorado at the Wilderness Medical Society annual conference, Monday July 24,
plus two workshops on Tuesday July 25th: Stretches That Harm, and Core Training Without Crunches. Information and registration:

NEW books are out - with hundreds more effective techniques, fully illustrated, than would fit on my web site articles, and for all of you who can't get to the workshops:

"Healthy Martial Arts"
Huge wealth of information for training body and mind. eBook and Print Edition.

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Monday, July 10, 2006

Recommendations of the World Congress on Drowning

Appendices to Recommendations of the World Congress on Drowning
Amsterdam 26 – 28 June 2002
Overview recommendations task force Diving (breath hold, scuba and hose diving)

During the World Congress on Drowning, experts of the task force Breath hold, scuba
and hose diving have finalised a consensus document on a variety of topics.
It was agreed that
1. Well-constructed national regulations have been effective where enforced and
that any significant improvements in health and safety would arise only from a
more inclusive definition of working divers and a wider application of existing
2. Self-regulation within the world-wide recreational diving industry continues to
be the practical route for further improvement but that there is a need to counter
a perception that there is a conflict between commercial interests and safety.
3. The training agencies comply with international quality assurance and control
procedures (QA/QC) such as the International Standard ISO 9000 series and
also encourage independent monitoring to assure the effective and safe use of
existing and new procedures.
4. Subsistence fishermen who are predominantly found in the poor countries
around the world, use equipment that is minimal and that their training,
regulations and medical support appear to be zero.
To improve diving-fishermen safety and reduce drowning there is a need to
collect data on accidents and drowning among representative samples of diving
fishermen around the world.
This should be followed up with international non-governmental organisations
(NGOs), other charities and appropriate UN development initiatives so that
existing academic societies, training organisations and others could deliver
suitable medical and diving advice and training for fishermen compatible with
the limits of available local resources.
5. The collection of diver morbidity and mortality data and the associated
contributory factors for each incident is a necessary first step in reducing
drowning incidents among divers. Also needed are the denominator data that
will allow the calculation of risk.
6. Recreational divers are free to dive when, where and how they like but the diver
also has an obligation to the public. Any underwater accident to a diver can put
buddy divers and rescuers at considerable risk.
7. Greater stringency is needed in the assessment of the physical, mental and
medical fitness of all who choose to dive. A single assessment of fitness for
diving at the beginning of diver training should not be considered valid
throughout the rest of the diver's life. Re-assessments are recommended at
intervals that may diminish with advancing years and re-assessment may also
be needed after illness or injury.
8. To give a medical opinion on a diver's fitness, the doctor should have prior
knowledge of the unique hazards faced by a diver. Whenever possible, the
medical assessment should be conducted by a doctor acknowledged as
competent in this special subject. It is recommended the training of diving
doctors, both for the medical examination of divers and also for the treatment of
medical emergencies in diving, complies with guidance such as that published
by the European Diving Technology Committee (EDTC) and the European
Committee for Hyperbaric Medicine (ECHM). Periodical revision training is
also important.
9. The mental, physical and medical standards of fitness in each category of
diving should be harmonised internationally.
10. Greater emphasis should be placed at all levels of training on the causation and
prevention of in-water fatalities.
11. After some 3 to 5 years without regular diving, the individual should be subject
to a formal re-assessment of competence before re-entering the water.
12. The policy of training children as young as 8 years old to dive should
emphasise the immaturity of mental outlook that many young persons may have
when an emergency occurs.
13. Emergency procedures should be consistent with a variety of equipment in a
variety of configurations.
14. Programs of refresher training should be established to maximise practical re-learning
and updating of basic emergency skills. This is needed particularly
after an individual's equipment has been modified.
15. Self-rescue and buddy-rescue procedures should be compatible with the
equipment used and the environmental conditions.
16. Training of rescuers should include the procedures for recovery of the victim
from the water into a boat and transfer of the patient from the deck of a boat to
a helicopter or some other emergency transport vehicle.
17. Hand signals and basic procedures used in diving emergencies, whether at
depth or on the surface, should be standardised and promoted through rescue
and diving agencies throughout the world.
18. Rescuers must be made aware that the treatment of drowning in a diver might
be complicated by other medical conditions such as carbon monoxide
poisoning, envenomation and omitted decompression arising from that same
19. National and international standards of medical care should be written for all
medical emergencies in diving by suitable academic bodies.
20. Drowning is mostly a diagnosis of exclusion and often is a presumptive
diagnosis based on purely circumstantial evidence. All diving-related deaths
should be thoroughly investigated, including a complete autopsy, evaluation of
the equipment and a review of the circumstances surrounding the fatality by
knowledgeable investigators with appropriate training and experience.
The post-mortem examination of a drowned diver should be conducted by a
pathologist who is knowledgeable about diving (or who is advised by a doctor
who is knowledgeable about diving).



The $2,000.00 scholarship is designed to assist the recipient to attend the UHMS Associates Annual Scientific Meeting (ASM).


The nominee must be a member in good standing of the UHMS Associates;

The nominee must submit an abstract, and deliver the presentation at the upcoming ASM.

If selected, the scholarship recipient will agree to:

1. Submit the abstract and paper for publication on the Associates website education column.

2. Submit his or her bio and photograph for viewing on the Associates website.


A. Be relatively new to the field, and who has already shown great promise (enthusiastic and self-motivated, who has obviously spent non-compensated time furthering their knowledge-base). Preference will be given to those who have made "significant" contributions (published a pertinent article, assisted in the creation of the standards for hyperbaric staffing and patient care, acted as faculty for related training programs, etc.), or;

B. Has been employed in the field of diving/hyperbaric medicine/technology for some time and has yet to attend the ASM (the reason being lack of financial means rather than lack of interest). It would be considered that the early opportunity to attend the meeting might further motivate and stimulate this individual to achieve administrative and clinical advancement, or;

C. A long-standing member who has worked tirelessly, and without expectation, to further the goals of the Associates and to advance the field.


Nominations can be made by any UHMS Member, but the nominee can only be an ASSOCIATE Member in good standing. The nomination must be signed off by the nominee and the nominee’s supervisor from the nominee's facility or organization who is also a member of the UHMS. Nominations are made by completing the application form. The deadline for nomination is 150 days (5 months) prior to date of the ASM for that calendar year. The justification statement on the application form must include how the nominee fulfills the selection criteria (above). Applications and resumes must be emailed to Education Committee Chair who will then screen applications for validity under the selection process. Partially completed applications will not be accepted for consideration. The Education Committee will review all accepted applications and vote to select the scholarship recipient for that year. The winner will be notified by letter. Formal announcement will be made at the Annual Meeting, the Associates website and in the next edition of Pressure. An official presentation of the award will be made during the UHMS Annual Meeting. A photograph and bio of the recipient will also be posted on the UHMS Associates website.



Legal Article: Diver hit by jet sled

Diver hit by jet sled: Negligent operation: Failure to properly diagnose and treat: Decompression illness: Fractures: Settlement
Law Reporter, Jun 2003

Errickson v. Horizon Offshore Contractors, Inc., U.S. Dist. Ct., E.D. La., No. CV01-2133-"C", Nov. 4,2002.

The diver, Errickson, 36, suffered multiple fractures to his left leg while he
was helping place a jet sled on an underwater pipeline 100 feet below the surface when the sled was dropped on him.

He was raised rapidly to the surface causing him to suffer decompression illness from being raised to the surface too rapidly after the incident. No recompression treatment was provided by his employer. Errickson underwent two surgeries to repair his orthopedic injuries. He incurred medical expenses of approximately $200,000, paid by his employer.

Errickson, who had earned approximately $40,000 annually as a commercial diver, is unable to return to that work. He is now pursuing education toward an alternative career.

Errickson sued his employer under the Jones Act, 46 U.S.C. [sec] 688, alleging failure to properly plan and supervise the operation-which allegedly took place under unsafe sea conditions-and failure to ensure that the rigging to the sled was safe. Plaintiff also alleged defendant was vicariously liable for the hospital's failure to properly diagnose and treat his decompression illness. Following mediation, the parties reached a settlement for $1.4 million.

Plaintiff's experts were John W. Grimes, vocational rehabilitation, Lafayette, La.; G. Randolph Rice, economics, Baton Rouge, La.; and John W. Thompson Jr., neuropsychiatry, and Paul G. Harch, hyperbaric medicine, both of New Orleans, La.

Defendant's experts were Kenneth Adams, neuropsychiatry, Ann Arbor, Mich.; and Kenneth Boudreaux, economics, New Orleans, La.

Plaintiffs Counsel

*Bobby J. Delise, Metairie, La.

*Alton J. Hall Jr., Metairie, La.

*R. Justin Garon, New Orleans, La.

*Scott E. Silbert, New Orleans, La.

Delise has attended the UHMS course on Medical Fitness to Dive and now gives lectures to the course as part of the curriculum.

NORTHEAST CHAPTER Of the UHMS Conference/Chapter Meeting

Lisa Wasdin, UHMS sends this information:

Conference/Chapter Meeting

(pre-courses: November 3)

Hartford Marriott Downtown
200 Columbus Blvd., Hartford, CT