Although not officially a subset of Aerospace Medicine, the discipline of Dive Medicine has many similarities both in practice and spirit. The US Navy and both recreational and competitive scuba organizations utilize physicians specialized in Dive Medicine to address the physiological stressors of underwater exploration.
Many of the unique medical conditions affecting divers such as decompression illness and trapped gas also affect aviators due to pressure changes. Similar to assessing fitness for flight, dive medicine specialists have to consider the overall health of a diver and clear them medically prior to SCUBA. Hyperbaric Medicine, a medical fellowship in itself, is often used to treat diseases that affect both aviators & divers.