The purpose of this chapter is to familiarize divers with U.S. Navy
surface-supplied procedures.
Surface-supplied mixed-gas diving is conducted with helium-oxygen
mixtures supplied from the surface by a flexible hose. Surface-supplied mixed-gas
diving is particularly suited for operations beyond the depth limits of air diving,
yet short of the depths and times requiring the use of a deep diving system.
Surface-supplied mixed-gas diving is also useful in the deep air diving range when
freedom from nitrogen narcosis is required.
