Torpedo failures - weather related.

[Iron Budokan]

Originally Posted by GJO

Although many of us think of the breaking waves that we may see at the sea shore or in shallow water, the long rollers of the North Atlantic are quite different. Here the length of the trough between wave crests may be more than sufficient to enable a torpedo to keep to a constant depth below the surface whilst following the shape of the wave - this would be especially true if the advice provided at Torpedo School was followed regarding positioning to enable the weapon to be fired at approximately 90 degrees to the wave direction.

ETA: In heavy seas, merchant ships (especially in the days of sail or steam) would choose to head into or away from waves rather than take them broadside on. Therefore, a torpedo fired at 90 AOB would be fired along the waves rather than against them.

This is interesting information, thank you!