In the case of ramming !!

[melnibonian]

I also think that you don't get renown if you sink a ship by ramming

U-Boats are not Triemes, they are supposed to run silent and fire torpedoes. In the book Iron Coffins the German HQ gave an order to U-Boats to try to stop the Allied Invasion in Europe (4/6/1944) by ramming the barges after having run out of torpedoes. All of the U-Boat commanders thought it as a ludicrous order as it was ordering them to commit suicide.