Danny Crowell preps for a 200-foot wreck dive off the Jersey Bight, 1999.

A C C E S S + R E S O U R C E S Abyss Exploration 101 Although tech diving is dangerous, it is also great adventure. Take the time to learn the risks involved before going deep. Below, some of the leading players in tech training. * Professional Association of Diving Instructors 800-729-7234; www.padi.com PADI's tech diving program will launch in January. Prices will vary with locations and instructors. • Global Underwater Explorers 800­762-3483; www.gue.com The average two- to three-person, five-day course is $600. Private classes run $1,100 to $1,600. * Technical Diving International 888-778-9073; www.tdisdi.com Course lengths vary according to diver's skill level and run $150 to $1,000. * International Association of Nitrox and Technical Divers 305-751-4873; www.iantd.com One- to eight-day classes range from $150 to $750. * American Nitrox Divers 800-229-2634; www.andihq.com Course lengths vary according to diver's skill level and run $495 to $700. * National Association of Underwater Instructors 800-553-6284; www.naui.org Classes vary in price according to length and region.

THE POMPANO BEACH incident resembles any of a dozen fatal accidents that occur each year in the elite, high-risk world of technical diving—a sport that involves descending beyond 130 feet, often in hazardous environments such as shipwrecks and caves, at times using breathable combinations of helium, nitrogen, and oxygen. And it is precisely the kind of event that throws the diving community into a fit of pained self-examination. Only now, the internal debate is being fueled by a broad institutional change: In January, an arm of the Professional Association of Diving Instructors, or PADI, the world's largest dive-training agency, will roll out its first technical-diving training program. The firm's new courses will make what many consider to be the hazardous fringe of the sport more accessible to the millions of sport divers around the nation.

This scenario—which concerns many veteran tech divers—could scarcely have been imagined back in the mid-1980s, when Bill Stone, a structural engineer from Gaithersburg, Maryland, first began experimenting with helium-based breathing gases to explore deep caves in Wakulla Springs, Florida. Stone and his team ventured more than three miles into underwater cave passages at depths exceeding 300 feet—far beyond the reach of ordinary compressed-air scuba. Though commercial and military divers had breathed "mix" (a blend of breathable gases) for decades, and Jacques Cousteau had used it to reach 400 feet in 1976, Stone was one of the first to apply it to recreational diving. By the early 1990s, with the support of a handful of specialized training and equipment vendors, the fledgling sport of technical diving began to take hold among more adventurous scuba fans.Today it is arguably the highest-profile segment of the sport.

PADI estimates there are three million sport divers in the U.S., but Technical Diving International, a school based in Maine, says that there are only about 200,000 technical divers in the entire world. Still, tekkies make a dent in the market disproportionate to their numbers. Each of these elite frogmen commonly spends as much as $5,000 on gear, including a specialized buoyancy-compensator device, a dive computer, and sometimes an underwater scooter. (A typical sport diver owns about $2,000 worth of equipment.) Tech divers also invest heavily in training courses. Which is where PADI comes in.

Considered the Microsoft of diving—a no-holds-barred competitor dominating the training industry—PADI claims to certify 70 percent of all new divers in the United States, and 60 percent of all divers worldwide. Its global network of about 100,000 retailers and instructors dwarfs that of the firm's nearest competitor, the National Association of Underwater Instructors. Some 200 staffers work for the private company, based in Rancho Santa Margarita, California. In a 1996 interview, PADI president John Cronin said the company pulls in more than $30 million a year from certification fees and the sale of instructional books and videos in 24 languages. It is a finely tuned marketing machine, built on untold scores of regimented dive classes.

Which is, in the eyes of many, exactly the problem. Making tech diving more accessible to a mass market is "like putting a civilian pilot behind the controls of an F-14," says attorney Bobby Delise, whose Metairie, Louisiana, firm built its practice on representing families of those killed in diving accidents. "You can't market life-threatening activities like tech diving and BASE jumping the same way you market other services. You have to play by different rules." He is concerned that would-be tekkies already take so many classes that they don't get enough real-world diving experience. "It doesn't make any sense for students with fewer than 100 dives to be taking a mixed-gas class," he says. "The bar is too low, and when a mistake occurs the price is too high."

Like alpinism, tech diving is brutally unforgiving—participants risk such physiological disasters as nitrogen narcosis, oxygen poisoning, and the bends. In 1998 and 1999, 28 out of the nation's 161 diving fatalities, or roughly 17 percent of the total, were tekkies. If that sounds unimpressive, consider that tech divers constitute a very small slice of the overall diving population. "I lose two friends a year," says Bridgeport, Connecticut­based technical diving instructor Joel Silverstein. (He's never lost a student or partner.) "Fatalities are part and parcel of technical diving."

PADI acknowledges that it is plunging into treacherous waters. "Our philosophy is that tech is not for everyone," says Karl Shreeves, a vice-president of Diving Science and Technology, the arm of PADI that will run the new tekkie program. "We're not going to market it that way. We don't expect huge numbers." But many tech trainers have profound philosophical issues with the firm's approach. PADI students progress through a sequence of written exams before advancing to the next level. Instructors must stick to the book and are given little or no leeway to improvise. By contrast, old-school tech trainers believe religiously that the experience of the instructor is everything and that rote rules just won't help beyond 200 feet, when problems must be solved quickly and instinctively.

Though Shreeves says PADI won't oversell the tech program, critics fear the firm's mass-market focus. "Tech diving is completely different [from sport diving]," says Dave Mount, the general manager of the International Association of Nitrox and Technical Divers (IANTD). "It requires an exceptional instructor with tremendous experience and currency." Shreeves counters that PADI has a proven track record and offers the industry's best quality-assurance program —asking students to critique their instructors. Further, he stresses that the new program will only accept students who have logged more than 100 dives, trained in specialites such as night diving, and have several certifications above the basic open-water level.

The Pompano Beach incident arguably demonstrates that not even the training organizations that specialize in tech diving have spotless records: At the time of the tragedy, Derek McNulty was an IANTD-certified instructor.

In some respects, PADI may usher in a higher level of professionalism for the sport. "PADI has a long history of creating outstanding [classroom] materials," says Bob Decker, the training director at Olympus Dive Center in Morehead City, North Carolina."In that manner they will raise the bar." But he also charges that the company has in the past been guilty of taking what he calls a "fast-food approach" by not insisting divers put in the time to pay their dues and gain critical experience.