Fire One! © 1979 Exidy.

Fire One! was a player-versus-player or player-versus-computer submarine showdown.

The primary objective of the game is to find and destroy the enemy's submarine, while avoiding the enemy's torpedoes. Through your virtual periscope you are free to launch one of your 8 torpedoes to take out any of the enemy's various ships for extra points. It takes some time to reload each torpedo tube, so you must be judicious in how you plan your attacks.

In addition to being able to control the left/right rotation of your periscope, the game also features a submerge button which you can use to temporarily hide from the enemy. Holding this button down keeps you hidden but also keeps you out of the action, allowing the enemy free reign over the seas.