This column is adapted from a chapter in my book, Scuba Physiological – Think you know all about Scuba Medicine? Think Again! The chapters in this book were originally written by scientists in the field of decompression research as part of a three-year project called PHYPODE (Physiology of Decompression). My (self-appointed) task was to rewrite their sometimes-complex research in a form accessible to all divers.

The waters off the coast of the US state of North Carolina are treacherous. Bad weather, rough seas, heavy current and inlets that are difficult to navigate are common. So why do underwater explorers consider this area to be a world-class dive destination? Because when you do get offshore, it is extraordinary.