As a scuba instructor I am often asked “what does scuba stand for?” The word “scuba” is an acronym for Self-Contained Underwater Breathing Apparatus. Webster’s Dictionary defines scuba (scu·ba) as “an apparatus utilizing a portable supply of compressed gas (as air) supplied at a regulated pressure and used for breathing while swimming underwater“. Although an acronym, the modern word scuba is acceptable in common case and does not need to be written as all capitals (SCUBA) nor with abbreviation (S.C.U.B.A.).
The acronym was coined by Dr. Christian Lambertsen in 1954. While at the University of Pennsylvania Medical School, Dr. Lambertsen worked on the first prototypes of rebreathers for military frogmen. He created the Lambertsen Amphibious Respiratory Unit, a.k.a the Lambersten Lung. Dr. Lambertsen gave these units the military code name of S.C.U.B.A. as they were a self-contained underwater breathing apparatus.
After his graduation from medical school, the Office of Strategic Services hired him as a 1st Lieutenant with the Army Medical Corps. He made significant contributions to amphibious units of the U.S. Military with his focus on breathing gases and decompression theory. Dr. Lambertsen laid the foundation for the modern-day rebreathers and for the use of enriched-air nitrox. He, along with Cmdr. Doug Fane, were the first to use rebreathers to exit a submarine in 1948.
Dr. Lambertsen went on to be medical faculty of the University of Pennsylvania. He is also the founding president of the Undersea Medical Society, now known as the Undersea and Hyperbaric Medical Society (UHMS). The U.S. Navy Special Warfare community gave him the distinction as “The Father of U.S. Combat Swimming”.