Sea Wolf is an arcade game by Midway, originally released in 1976. The player looks through a large periscope to aim at ships moving across the virtual sea line at the top of the screen, using a thumb button on the right handle of the scope to fire torpedoes. The periscope swivels to the right and left, providing horizontal motion of a targeting cross-hair. The cabinet features a mixture of video game and older electro-mechanical technology for player feedback. Using back-lit transparencies reflected inside the scope, the number of torpedoes remaining are displayed, as well as a red "RELOAD" light which lights up momentarily when the player has launched five torpedoes. Additionally, when ships are hit on the screen, an explosion "light" is reflected inside the scope. A blue overlay is affixed to the screen to provide a "water color" to the sea. Sounds include a sonar ping and the sound of the PT Boat racing across the screen. Sea Wolf is time-limited, with the player having an opportunity to win bonus time by reaching an operator-set score. The player's score is shown on the bottom half of the screen as well as the high score, one of the first known instances of a high score in a video game. Targets include destroyers, a fast moving PT Boat, and mines floating across the screen can that serve as obstructions.