Shallow Water Blackouts
Experts speculate that passing out as you near the surface is the most common cause of death in free diving.
The world governing body of free diving, AIDA, states that, “Anyone who has held their breath underwater has free dived.” But those of us who’ve touched the bottom of our local swimming pool have nothing on the seemingly fearless free divers who’ve plunged as far as 214-meters (702-feet) below the ocean’s surface on a single breath.
Women’s no-limits (or, weight assisted) record holder Tanya Streeter says that during a descent, “the brain signals to shut down oxygenated supply of blood to organs that don’t need it,” and at the bottom of a free dive, a diver’s heart rate drops to just 12 to 15 beats per minute. Amongst adventure sports, only BASE jumping is more fatal than free diving. Out of the estimated 5,000 divers in the sport, nearly 100 die yearly.