During this process, the surfaced submarine is vulnerable to detection since enemy radars quickly detect submarine masts or snorkels protruding above the surface.

An AIP system powers a submarine without using air from the atmosphere, which is essentially for conventional diesel-electric submarines. In the latter, large banks of electric batteries power electic motors that turn the submarine’s propellers. But the batteries quickly get discharged and the boat must surface every day or two to run onboard diesel generators (which require atmospheric air) to recharge their batteries.