Sailors load a Harpoon anti-ship cruise missile on to the Los Angeles-class fast-attack submarine USS Olympia (SSN-717) as part of the biannual RIMPAC maritime exercise.
The 1970s era anti-ship missile is now in its most advanced version, Harpoon Block II+, and is being augmented by a program to field new and more advanced missiles, such as the AGM-158C LRASM and the Norwegian Joint Strike Missile. However, with those new missiles being air-or ship-launched, for subs looking to poke a hole in a ship, it is either Tomahawk or Harpoon, for now at least.