A submarine simulation game set during an unspecified conflict. The back of the box says:
"Set sail on a voyage that could change the whole of your future to come. As midshipman in command of a U39 submarine and its 35 crew, you must stalk the deep in search of enemy craft - destroyers, corvettes and merchant shipping. Keep a watchful eye on your sonar, radio and radar navigation equipment for when contact is made you must strike with deadly speed.
Promotion to the admiralty beckons. This top flight simulation offers you many perilous missions in which to prove your sea worthiness."