HMS Porpoise (S01)

HMS Porpoise (S01) was a Porpoise-class submarine of the Royal Navy. She was launched on 25 April 1956, commissioned on 17 April 1958, and was sunk as a target in 1985. She was decommissioned in 1982 and sunk as a target in 1985 in trials for the Spearfish torpedo, for which purpose she was painted bright red. She had been used as a target while still serving with the Navy, in 1979 her casing, ballast tanks and vents were reinforced so that unarmed torpedoes could be fired at her without the risk of sinking her.