[jason210]

Ok. But if it was a problem in real-life then it means subs couldn't sink anything with a keel depth of less then (guessing) 7 ft.

It's also a bit demotivating if, after three hours of firing torpedos at stationary subchaser in Shanghai harbour, I can't sink her. What hope is that at sea, with waves and moving targets?

I think I'll ram some junks on my way back, out of spite.