Dolphins, whales, and other air-breathing aquatic mammals are perfectly adapted to underwater life. They spend most of their life underwater and venture to the surface only to breathe. On the other hand, humans are adapted to life in a dry atmosphere and can go underwater only briefly while holding their breath. With self-contained underwater breathing apparatus (SCUBA), humans may significantly extend their stay underwater. Whether on a single breath or scuba, diving involves stressors that result from breathing modifications, water immersion, and changing pressure as the diver moves vertically in the water. For fit and well-trained divers, diving stress is positive and causes spontaneous adaptations without divers being aware of it. This makes diving a relaxed and pleasant experience. DAN Research studies how the human body, especially the cardio-respiratory system, adapts to diving, why adaptation could fail, and who may be at risk.
Diabetes and Diving
Historically, DAN advised divers with insulin-dependent diabetes against diving because of the threat of a hypoglycemic episode underwater. However, two studies helped reevaluate the guidelines for recreational diving with diabetes.
Physical Fitness of Divers
Adequate levels of physical fitness are necessary to meet both typical and emergency demands of diving. But sometimes, guidelines have unrealistically high bars that not all divers can meet.