SSN-21 Seawolf is a submarine simulator game designed by John W. Ratcliff and published for MS-DOS systems by Electronic Arts in 1994. The player takes command of a US Seawolf-class submarine and fights in 33 missions with targets under and above water including Russian attack subs, destroyers, missile cruisers, aircraft carriers and frigates. Like its predecessor, Seawolf allows two players, on different PCs, to play each other via a modem, or null-modem cable, and adds the option of using anIPX local network which can provide a more reliable connection.