@ABWorsham:
Had the Germans Navy used bombers and fighters to escort U-Boats and help U-boats locate prey, British tonnage losses could have been much greater.
Germany did indeed use aircraft quite effectively (but in inadequate numbers) for reconnaissance purposes – specifically the FW-200 Condor. I’m doubtful about the U-boat escort concept, however, for a number of reasons.
First, there would have been a huge imbalance between the endurance (hours as opposed to weeks) and operational range of the planes compared to the U-boats.
Second, during the first half of the war, U-boats were at their most successful when they conducted surface attacks at night, a time at which aircraft would have been largely useless. Operating on the surface at night allowed U-boats to move at full speed if required (U-boats were quite slow underwater) while still remaining largely invisible (until the arrival of centimetric radar later in the war made visual detection a less critical factor).
Third, having escort aircraft accompany U-boats would be a dead giveaway – visible from a great distance – to Allied ships that there was a sub in the area, thus further compromising the U-boat’s primary advantage, which is the ability to conceal itself.
Fourth, arranging a rendezvous between a U-boat and an escort aircraft would have involved a lot of radio communication, which would have given Allied crytographers even more information with which to pinpoint U-boat positions. (The radio traffic between Doenitz’s HQ and his U-boats was already proving very valuable to the Allies.)
Fifth, one has to remember the purpose of U-boat escort aircraft would presumably have been to defend the subs by attacking enemy escort ships, which would have been a much tougher proposition than the role which Allied escort aircraft had in defending convoys from subs. Although Allied propaganda tried to convince the public that the mission of such aircraft was to destroy U-boats (which some did indeed do successfully), their most useful function was to scare U-boats into submerging. Submerged U-boats move more slowly than on the surface and use up more fuel, so this reduces their operational endurance. Submerged U-boats (again, despite what’s shown in films like Action in the North Atlantic) also have a tougher time lining themselves up for a torpedo shot than on the surface because of the speed differential between them and the target. Driving U-boats underwater was easy for Allied escort planes: basically, all they had to do was show up, without even necessarily dropping any weapons.