You command a group of escort warships shepherding a merchant convoy across the North Atlantic. You steer one; the rest hold station and screen their sector — press Tabuse Switch to take command of any of them. Wolfpacks of U-boats stalk the deep, but they fear your escorts: get close and they dive and run; they only dare surface to fire when no escort is near. Force the kill with depth charges for the deep, ram them on the surface, and your deck gun to swat torpedoes. How long can you survive?

Depth charges are limited — resupply at port. The clock is heavily compressed (never real-time): it runs fast by default (×3) — slow it toward ×1 with , / .with the Speed button for a calmer game.