SCUBA is an acronym that stands for Self-Contained Underwater Breathing Apparatus. The term was coined by Dr. Christian Lambertsen in 1954 as a new name for his earlier invention, the Lambertsen Amphibious Respiratory Unit (LARU). The SCUBA system allows divers to breathe underwater and move around comfortably without any connection to the surface. It consists of a portable supply of compressed gas, such as air, supplied at a regulated pressure and used for breathing while swimming underwater. Although the word SCUBA started out as an acronym, it has since evolved to common case in the English language, and there is no longer a need for abbreviation (S.C.U.B.A).