Sixty feet below the water’s surface off Key Largo, the Aquarius, the last underwater science habitat in the world, was caught in a maelstrom.

As Hurricane Gordon’s churning waves battered the giant yellow cylinder, Aquarius was reduced to auxiliary battery power. Worse, its generators had shut down and one had caught fire.

As the ailing vessel devoured its remaining power, those inside began a risky climb to safety up a rescue line to a 50-foot catamaran on the ocean’s surface. “A few times I thought the boat was going to go over,” recalls veteran diver Craig Cooper, who was on the scene at the time. “Six of us would grab the divers out of the water and power back up before the wave took us. We used everything but gaff hooks, hauling those guys out of the water like tuna.”

Commercial diving is, by anyone’s account, a dangerous business. Whether you’re engaging in underwater salvage and construction, inspecting offshore oil and gas rigs, operating marine science stations, or hunting for sunken treasure, you are at the mercy of a hungry ocean. A study by the Centers for Disease Control and Prevention found that America’s roughly 2,000 full-time commercial divers suffer an on-the-job death rate of almost 40 times the national average for other workers.

Fortunately, in the case of the Aquarius, the entire crew of scientists and divers escaped from the 1994 hurricane, but not all deep-sea divers are so lucky. Cooper, a big sun-reddened man, is pensive as he recalls close friends and colleagues he’s lost in the murky deep. One of them, who was killed in 1979, was a buddy diving with Cooper when the Ixtoc oil platform exploded in the Gulf of Mexico.

“No method to the madness”

Obviously, humans are not made to breathe under water, but even when relying on complex, often bulky, breathing equipment, commercial divers are still subject to every whim of the turbulent aquatic environments. The cold saps your strength, the currents can be torturous, and visibility is often bad. As if that weren’t enough, you have to watch out for mud, sand, sharks, and stinging flora and fauna, not to mention potentially deadly hyperbaric pressures, which are those above the normal atmospheric pressure.

As many nondivers may remember from watching actor Lloyd Bridges writhing or doubled up in agony in the 1960s television show “Sea Hunt,” hyperbaric pressures are a serious threat. As a diver descends, the increased pressure from the water causes his breathing gas (usually compressed air) to be absorbed into his body tissue at a higher rate than occurs on the surface. Then, as he ascends to the surface of the ocean, the pressure decreases and nitrogen is released into the bloodstream and tissues. The rate of ascent as well as the depth and total diving time determine the nitrogen load. If the diver hits the water’s surface too quickly, too much nitrogen can flood the body, leading to the serious, sometimes fatal, decompression illness known also as “the bends.”

A study by Swiss researchers suggests that divers who have a relatively common heart defect known as a patent foramen ovale, or PFO, are more likely to get the bends. A small opening between two chambers of the heart, PFOs occur in about a quarter of the population. The defect is usually harmless; however, divers with PFOs get the bends four and a half times more than those without the defect, according to the study.

“It’s a hazardous profession, no doubt,” says Frances Stepp, former president of the National Association of Commercial Divers (NACD).* The Coast Guard updated its outdated regulations in 1998 to bring them into alignment with the standards of the Occupational Safety and Health Administration (OSHA), but Stepp notes that the rules are only sporadically enforced.

Moreover, many accidents take place offshore, which allows unprincipled or reckless administrators to cover up accidents. “While the companies are supposed to notify authorities within 24 hours, by the time inspectors get there the shifts have changed and parts have been thrown overboard,” Stepp complains. “There’s no method to the madness.”

“Safety lagging behind that of Europe

Work safety has gotten better in recent years with the introduction of superior diving medicine, more hyperbaric chambers in hospitals, and robot submarines to use in tackling some of the deepest, most dangerous work in the offshore oil industry.

Safety will likely continue to improve as more resources are put towards it. OSHA and the Association of Diving Contractors International (a non-profit group representing 600 diving companies) finalized an agreement in 2005 to develop and implement educational safety courses for commercial divers. The pact also aims to share information like hazard and workforce trends, and to prioritize development of outreach programs.

According to Stepp, European divers in the North Sea boast far fewer accidents and fatalities, despite waters that are far colder and more treacherous than those of the Gulf of Mexico. Stepp attributes this to stricter standards and enforcement by British and Danish companies as well as the government agencies that oversee them.

Nonetheless, U.S. regulation of the industry is better than it used to be, says Jerry Gauthier, an ex-diver and former president of the Association of Diving Contractors.

“Back in the late ’60s it was anything goes,” Gauthier says. “People were killed and it was a lot riskier industry.”

Many older commercial divers have gone on to expand their roles in the industry by making the transition to work site supervisors, pilots of remote operated vehicles (ROVs), and even company officials. their presence provides a wealth of experience that’s proving good for both the contractors and their divers in the water.

“Experienced divers know you can’t always just muscle stuff underwater,” says Cooper, who is operations director of Aquarius. “You have to use your mind, not just your muscles.”

“Tips for diving safely

  • Keep healthy and fit.
  • Know the OSHA and US Coast Guard safety standards for commercial diving operations by heart. It’s in your best interest to follow them at all times.
  • If conditions at your work site are dangerous or not in compliance with current diving standards, talk with your employer. If this doesn’t work, contact your local OSHA or Coast Guard office.
  • Avoid alcohol and other drugs before, during, and after diving.
  • Don’t dive when you’re ill.
  • Maintain high levels of hydration by drinking enough water.
  • Let other divers know which companies are interested in diver protection and which appear to be more interested in the bottom line.
  • Studies suggest that older divers have a greater risk of decompression sickness, so be especially careful while ascending if you’re in this age group.
  • Avoid the motion-sickness drug dimenhydrinate (Dramamine) before diving. Recent research from a University of Pittsburgh, Pennsylvania team indicates it may impair your memory and performance underwater. The researchers recommend pseudoephedrine (Sudafed) instead.

*Since this article was written, the National Association of Commercial Divers has been disbanded.

Further Resources

Association of Diving Contractors International


Diving Medicine Online



Interview with Craig Cooper, diver and operations director, Aquarius undersea research station.

Interview with Frances Stepp, president of the National Association of Commercial Divers (since disbanded)

Interview with Jerry Gauthier, former president of the Association of Diving Contractors

Emergency Diving Medicine. Diving Medicine Online. http://www.scuba-doc.com/~scubadoc/EmgDvMd.htm

Diving Accident Fatalities. Diving Medicine Online. http://www.scuba-doc.com/~scubadoc/EmgDvMd.htm

Bureau of Labor Statistics. Commercial Divers. May 2007. http://www.bls.gov/oes/current/oes499092.htm

Schwerzmann M, Seller C et al, Relation between directly detected patent foramen ovale and ischemic brain lesions in sport divers. Swiss Cardiovascular Center Bern and University Hospital, Annals of Internal Medicine; 134 (1):21-4

Bailey, CE, et al. Current management of patients with patent foramen ovale and cryptogenic stroke: our experience and review of the literature. WMJ: Official publication of the State Medical Society of Wisconsin.

Medical encyclopedia: patent foramen ovale.National Institutes of Health.

ROV background. Remotely Operated Vehicle Committee of the Marine Technology Society. http://www.rov.org/info.cfm

Taylor DM, et al. The psychometric and cardiac effects of dimenhydrinate in the hyperbaric environment. Pharmacotherapy 2000, Sept:20(9):1051-4.

University of Pittsburgh News Bureau: University of Pittsburgh researchers find some over-the-counter medicine may affect scuba divers’ performance.

© HealthDay

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