I've been watching this incredible video about the Battle of Jutland, and at one point, it mentions that the British Grand Fleet was forced to break off from its pursuit of the German High Seas fleet because of a torpedo attack. That got me wondering why u-boats weren't used more often in large fleet engagements. I can only imagine all those large dreadnoughts strung out in a battle line would be sitting ducks for a torpedo attack, especially one that was covered by surface vessels. And yet the role of U-boats seems to have been mainly for raiding.

Was it just a matter of submarine warfare not being considered gentlemanly? Or am I as an armchair admiral overlooking some more obvious explanation?