A co-worker of mine used to do some work associated with torpedos. One of the more interesting things I have learned is that modern torpedos don't try to "hit" the ship they are shot at. Instead, they blow up under them.
Enter the MK 48 ADCAP (ADvanced CAPability) torpedo. It weighs about 3,500 pounds and carries just under 600 pounds of high explosive (roughly equivalent to a half ton of TNT).
It's designed to detonate 30 or so feet directly under the keel of the target ship. This turns out to be much, much worse for ships than you might expect.
The pictures below are of a single MK 48 ADCAP blowing up below the HMAS Torrens (Australian).
This article has all the salacious details.
Moral of the story, don't be on a ship that gets shot with one of these. It'll ruin your whole day.