You have to keep in mind here that regardless of what we like, SH5 is in the looney bin, having thoroughly changed a submarine simulation into a hokey arcade game.
Let me explain. In the war, recognition manuals of both sides were awful. In the American submarines, they determined that over half the targets shot at were completely misidentified! Most of those which were identified properly had erroneous information in their recognition manuals.
Basic information, length,masthead height, cabin configuration and heights, were just wrong. Many ships didn't even have an entry at all!
And that makes sense. In order for SH5 to be historically plausible, the German Navy would have had to rent every single Allied ship on the ocean, individually taken each ship to a German harbor of your choice and carefully measured all the parameters of each of thousands of ships. Needless to say, such an undertaking would have bankrupted the Third Reich, even if the Allies were dumb enough to consent to such a scheme.
In fact, great measures were taken to distribute misinformation about the characteristics of ships, done with the knowledge that enemy submarines would be using this info to shoot in their general direction. The Japanese, for instance, sawed off masts, installed fake cabin profiles and distributed false information onthe lengths and capabilities of their ships. They went so far as to build ships which were scale models of other ships, built, in the case I read abut to half scale! What would THAT do to your precious range measurement? Hmmmmm?
Actually, the Kreigsmarine used targeting methods that assumed all measurements of enemy shipping were wrong. They didn't even require target identification to hit. The US Navy, however, relying on their fancy technology (sound familiar?), used the recognition manual to garner masthead height and ship lengths in order to calibrate torpedo targeting. Garbage in--garbage out. US percentage of hits was markedly lower than that of the Germans.
As usual, SH5 has it wrong. That's one of the reasons why SH4 is a better submarine simulation.