DA,
Man..I believe this is because of the torpedoes.
They had a LOT of problems with the Mk14, and one things that was fairly commom was that a torpedo hitting a target in an angle of 90º, would do a clang, but not a bang (the detonator would be set, but the explosives wouldn't go off).
If you wanna more info, please read thie very interesting article on the Wikipedia:
"In 7 out of 10 of these trials, firing mechanisms bent, jammed, and failed with the high inertia of a straight-on hit (the prewar ideal).
[46] A quick fix was to encourage "glancing" shots
[47] (which cut the number of duds in half)..."
See the link:
http://en.wikipedia.org/wiki/Mark_14_torpedo
Have fun..errr...Good Hunting, sailor!