Nuclear-Powered Attack Submarine (SSN)

A nuclear-powered attack submarine (hull symbol SSN) is a multi-role boat whose reactor gives effectively unlimited submerged endurance, limited only by food and crew, for anti-submarine and anti-surface warfare, land-attack with cruise missiles, intelligence collection, and special-operations support. Unlike the SSBN, it carries no strategic ballistic missiles. Its speed and endurance let it escort carrier groups, trail adversary submarines, and operate independently far forward.