Ironically, it seems that the best version of a type VII U-boat was one that hasn't been built.

They should have built a third diesel engine, giving the U-boat one or two more knots of speed, and serving as a backup engine. It seems that the ones they had often gave trouble.

A third engine would have required a slightly longer-built hull which in turn would have served two other critical purposes:

1. It would have been possible to add bigger sized fuel tanks, beyond the ones enlarged already in the improved type VIIB version. This would have been a great help in the Atlantik missions, especially for those U-boats that came all the way to the US.

2. A longer hull would have created somewhat more space for crew and provisions, again, especially for longer exploits.

Johannes