Anti-Sub Patrol is a 1 - 2 player naval strategy game for the Atari 400/800.
The player controls a military vessel, that must hunt for two submarines on a large 13 x 19 grid. The player moves about the grid, and has the ability to scan for submarines in each quadrant they move into. When the player is adjacent to a submarine, they have the option to launch a depth charge and set the depth of the explosion. If the player correctly ascertains the location and depth of the submarine, it is destroyed. Enemy submarines will move one quadrant to a new location if they are threatened and not destroyed, and the player must ascertain the new location. The player has limited fuel to complete their task, as well enemy submarines will fire back at the player, and can destroy the player's ship. The player is victorious if they destroy all enemy vessels.