Realistic attacks!

[siber]

Hi guys and gals!

I was wondering; how many torps would a real life captain fire at a target? Would that number change depending upon whether the target is alone or in a convoy, or merchant or warship?

To be honest, I feel that the 1 torpedo per ship rule results in vastly unrealistic tonnage scores. Why are we all so good here, but (in general) uboat's averaged only few ships sunk each? What's the unrealistic factor? The number of torpedos fired in the salvos?

At the moment, in my Type IIA (Jan. 1940) I'll generally fire 2x spreads of two torps in a patrol, saving one torp for the return journey. However, how would I fire torps if/when I upgrade to a VIIB to be faithful to real life tactics?

More torps fired = better chance of hitting, but fewer salvos available.