Dive Medicine for Divers: Part 3, represents advanced knowledge development for divers interested in better understanding diving medical and safety topics. It includes topics on gas toxicities, the causes and mechanisms of drowning and the uses of an otoscope for examining a diver’s ears. There are also instructor-led topics on calculating partial pressures of gases, the causes of drowning for divers, legal issues with providing care in an emergency and learning to use an otoscope.