It is a textbook torpedoing! The torpedo is set to run nice and deep, and as it passes underneath the ship, the detonation circuit senses a change in the magnetic field and triggers the explosive, neatly snapping the ship’s keel, breaking its back, and sending it down with incredible speed. For the next five or ten minutes, bales of brown stuff erupt from the water, released from the cargo holds as the ship plummets towards the bottom. It gives the whole scene an unexpectedly festive air.