“When freedivers dive deep they activate a set of physiological reflexes that act as the first line of defense against hypoxia. Collectively termed either the diving response or mammalian diving reflex (MDR), the mechanism controls the shift of blood to the brain and heart, functioning in tandem as an important oxygen-conserving mechanism, not only in freedivers, but also in whales, penguins and seals (Figure 1). In fact, this amazing physiological phenomenon was first observed in deep diving mammals as early as the 1900′s, but until as recently as the 1950′s it was thought that humans did not possess the reflex.” – Erik Seedhouse

“For an equivalent change in depth the risk of barotrauma is greatest near the surface, a fact explained by Boyle’s law. A breath-holding free diver rising from 33 feet to the surface experiences a change in ambient pressure from two to one atmospheres. If the lungs fully expand within the chest cavity the lung volume will double. By contrast, a 33-foot rise from 99 to 66 feet depth (i.e., from 4 to 3 atmospheres) would maximally increase a free diver’s lung volume only 33 percent, posing less risk of a barotrauma.” – Erik Seedhouse

“The Orange County Register reports on a sighting of a great white shark, spotted two miles offshore near Doheny State Beach Sunday by a whale watching charter boat.”

“(Drew) had just passed an initial SEALs triathlon assessment a couple of days earlier, and was most likely practicing a 50-meter underwater swim while holding his breath…”

“Vertical Blue, a freediving school based in the Bahamas run by freediving world record holder William Trubridge, has teamed up with world-renowned yoga instructor Simon Borg-Oliver and mental coach Tim Carroll to offer a ‘Master Class for Freediving’.”