Surface-supplied diving is diving using equipment supplied with breathing gas using a diver's umbilical from the surface, either from the shore or from a diving support vessel, sometimes indirectly via a diving bell. Wikipedia

A hose used to connect a surface-supplied diver to a supply of breathing gas remotely provided on a diving support vessel or diving bell, often combined with other services in a bundle referred to as an "umbilical cable", more accurately referred to as the primary or main gas supply hose or air hose. When used alone it is often called the air line. Wikipedia Disambiguation

A form of deep diving using an umbilical that supplies air, power and communications from the surface to the diver, who wears a diving helmet. This is the traditional diving with a diving helmet and air hose. Wiktionary