Steve Bennett, a 20-year-old from Tarpon Springs, went free diving about 70 miles off Boca Grande in the summer of 2008, hoping to shoot some wahoo or amberjack.
"I was on my way up and passed my buddy at about 30 feet," said Bennett, a walk-on with the University of Florida football team. "I was 10 feet from the surface, then Bam! I blacked out. One second I was there, the next I was unconscious."
Bennett dropped his spear gun and began to sink to the bottom. Luckily his dive buddy, Cameron Kirkconnell, was able to put a shot through Bennett's fin and drag him to the surface.
It took Bennett's friends four minutes to revive him. He then spent another four days in the intensive care unit of a local hospital.
"I was lucky," said Bennett, who still dives without scuba tanks using breath-holding techniques. "I don't think I'd be here if it hadn't been for Cameron."
Mark Wasfy, a 31-year-old electrical engineer from Jupiter who has a vacation home in Sarasota, was free diving in 65 feet of water off Bradenton in August when he blacked out.
"My mind is a blank," he said. "I remember going by buddy's house at 6:30 in the morning, then the next thing I knew, I am waking up in ICU three days later with a tube down my throat."
Wasfy later learned that two of his friends found him unconscious on the bottom.
"They said that when I got to the surface, I wasn't breathing and had no pulse," Wasfy said.
Fortunately, a helicopter from Bayfront Medical Center got there quickly.
"It was pretty crazy," said Wasfy, who still free dives. "I probably won't push it that deep ever again."
Last month, about 25 miles off Venice, Russ Harris, a 22-year-old former Maryville (Tenn.) College football player, was free diving with friends when he also succumbed to what is commonly called "shallow-water blackout."
Free divers hold their breath. As a dive goes on, the oxygen starts to run out. But it is the buildup of carbon dioxide in the bloodstream that causes the desire to breathe, not the lack of oxygen. A diver who hyperventilates before going down can "blow off" carbon dioxide and stay down longer. But this can be dangerous, because the brain doesn't know the game and shuts down when the oxygen is used up.
Fellow divers found Harris on the bottom, but it was too late. He became another statistic in what many in the dive community believe is an epidemic of free-diving deaths.
"It is a huge problem," said Bill Hardman, a St. Petersburg scuba diving instructor who teaches a free-diving course at his Aquatic Obsessions shop. "I think a lot of these accidents could be avoided if these kids get a little formal instruction."
While shallow-water blackout can affect divers of all ages and levels of ability, it appears to be more prevalent among younger divers. Accurate free-diving statistics are not available, but one diving interest group counted 34 deaths worldwide and four injuries in 2006. More than half of those happened in the United States, and 60 percent of U.S. deaths occurred in Florida.
Some experts put those numbers much higher and say deaths have increased in recent years because of the sport's increasing popularity.
Miami resident Julie Richardson nearly lost her sons, ages 16 and 20, to shallow-water blackout in the spring of 2008. Since then, she has worked to promote safe diving on her Web site, www.divewise.org.
"Education is the key," she said. Like Hardman, Richardson believes many lives could be saved if divers followed these basic rules:
• Dive with a buddy: Partners should have comparable skills. Do not dive alone.
• Take turns: One diver should watch the other from the surface; one up, one down.
• Wait 30 seconds: After surfacing, a diver should be observed for 30 seconds — the time it takes for inhaled oxygen to reach the brain.
• Breathe sensibly: Excessive predive breathing can critically lower carbon dioxide — the trigger that tells the body it is time to breathe.
• Weight properly: Overweighting will cause a diver to sink after blackout, making rescue difficult.
• Ditch the weight belt: When a diver feels at risk or is involved in a rescue, eliminate the extra weight.
• Rest between dives: To recover from oxygen depletion and carbon dioxide buildup, rest twice as long as the last dive time.
• Be prepared: Planning ahead for an emergency can mean the difference between life and death.
November is peak free-diving season on Florida's west coast. To help educate new divers, several of the world's best will hold a symposium in St. Petersburg on Nov. 14. Speakers include Richardson, world record holder Martin Stepanek, 2009 World Cup Invitational champion G.R. Tarr and 2009 Florida State free-dive spearfishing champion Sasa Bratic.
Terry Tomalin can be reached at (727) 893-8808.