For our island communities in the Keys, scuba diving is more than just a hobby. For many it is a way of life. Diving draws visitors and residents alike to the clear, warm waters that surround us.</p><p>Diving has been proven an enjoyable, quite safe undertaking when some basic rules are followed, but it is not without risk even in the best conditions. Alex F. Brylske, professor of marine science and technology at Florida Keys Community College, gave a presentation titled “Dive Safety: New Insights and Fresh Perspectives” on Wednesday, Dec. 16 at the History of Diving Museum in Islamorada. </p><p>Brylske is also a training consultant for Divers Alert Network (DAN), a dive safety organization based at Duke University in Durham, N.C. His talk and PowerPoint presentation contained many DAN statistics concerning diving accidents and fatalities and advice on how they can be prevented.</p><p>“We have been gaining insight into a subject that few people have addressed,” Brylske said. “That’s how the mere fact of being under water has a significant impact on your respiration.”</p><p>Physical fitness, age, heart disease and a divers’ sex have also been studied and analyzed by DAN. Brylske said fatal diving accidents are sometimes hard to dissect because the cause of death is often determined to be drowning, but drowning may be the end result that was initially caused by some other problem like a heart attack or respiratory issue.</p><p>“DAN studied almost one thousand recreational scuba deaths and they found that about 40 percent were due to insufficient gas supply, 20 percent were due to entrapment and 15 percent were due to equipment problems,” he said. “There were some other causes, but those were the biggest ones.”</p><p>Having insufficient gas supply simply means the diver ran out of air or whatever gas they were breathing, a condition that Brylske said is entirely preventable.</p><p>“This is one of the issues that is much easier to avoid than to deal with later when there is a problem,” he said. “You might say that you would never start a dive without a sufficient air supply, but you need to stop and think long and hard about that. The amount of air you need for a dive is going to depend on the conditions, the depth, your psychological state, the weather and more.”</p><p>Brylske said many divers become accustomed to how long a tank of air normally lasts, but they don’t consider factors such as strong current, increased physical exertion, a deeper dive than they typically do or other reasons that could cause the supply to be depleted more rapidly.</p><p>Well-trained divers know the value of backup air systems and how to use them, but Brylske said it is important to practice those skills periodically so they will be fresh if they are needed in a real emergency.</p><p>Physical fitness is another key to safe and enjoyable diving and Brylske said the reasons are more than the obvious improved heart and lung function that regular exercise and a sensible diet provide. </p><p>Decompression sickness, commonly called the bends, happens when nitrogen gas that is absorbed into the bloodstream while diving comes out of solution and forms bubbles that can block arteries or veins, or gather in a divers’ joints. Bubbles in the blood vessels can cause blockages that result in a heart attack or stroke. Bubbles in the joints can also cause debilitating damage. DAN research has found that microbubbles form in a divers’ body on nearly every dive but are not large enough to be felt or to create an obvious health risk. Brylske said research on animals has shown that a higher fitness level decreases the formation of microbubbles.</p><p>“From both a physical conditioning perspective as well as decompression safety, maintaining a reasonable level of physical fitness is good,” he said. “The question becomes what level of fitness is sufficient. We can’t answer that across the board. The guideline is to be able to meet the physical demands of the situation. If you are diving and come back huffing and puffing, that’s a good indication that maybe part of that problem is your physical condition.”</p><p>Age can also play a role in a divers’ health and safety. Brylske said the average age for recreational divers is now 44, and that is increasing approximately 18 months per year. This is not only because certified divers are aging, but is also largely due to new divers not entering the sport until they are well into their 40s or beyond. DAN statistics show that one quarter of dive fatalities for those over 35 years old are heart related.</p><p>“One of the biggest concerns we have in recreational diving is we are just not getting enough kids into this sport,” Brylske said. “When I learned to dive as a kid, diving was an exotic, exciting thing to do. To get a kid’s attention and get them turned on to diving is a real challenge today.”</p><p>A wise diver will alter his diving style as he ages, Brylske said. </p><p>“There’s a lot of self honesty required and a willingness to adjust the kind of diving you do,” he said. “I don’t dive like I’m 20. I don’t even dive like I’m 40. You should be particularly mindful if you have a history of heart disease or other risk factors. You need to make informed decisions.” </p><p>When it comes to diving, women are apparently winning the battle of the sexes. Brylske said most arguments against women becoming divers and not being able to outperform men don’t hold water. One myth is that women don’t have the strength to dive safely.</p><p>“You don’t have to be [former bodybuilding champion] Arnold Schwarzenegger under water. What you need is to have decent aerobic capacity and stamina,” Brylske said. “That’s not muscular strength. So that is not really an issue for women in diving.”</p><p>Brylske said DAN discourages women from diving while pregnant, as nitrogen absorbed into the mother’s blood is passed on to the fetus, but the unborn baby is not nearly as efficient at eliminating that nitrogen from its system, since its lungs are not functioning as it gets all life support from the mother.</p><p>The History of Diving Museum’s next special program, “How Deep Sea Diving Changed the World,” will be presented Wednesday, Jan. 20 at 7 p.m.