Hi!
Allied convoy escort radar is much more of a help to the Allies than it is to your U-boat. The reason is that the escorts' radar prevents you from approaching and attacking on the surface, thus denying your U-boat the maneuverabilty and ability to rapidly re-engage the convoy that a surface attack brings, and which the early U-boat aces,
e.g., Kretschmer, Prien, and Schepke, used to great advantege before the escorts generally had radar. You may win a tactical victory while submerged by bagging a couple of ships, but the Allies win the strategic victory because the other 30-40 ships will arrive safely.
Denying you this tactical advantage far outweighs any advantage you will obtain by being able to use their radar emissions generate a track, especially since you can generate the track anyways by other, historical means; however, since you've taken the effort to point out this exploit, which has existed since stock
Silent Hunter III, we will take a look and see if we can close it up a bit.
Thanks!
Pablo
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"...far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy much nor suffer much, because they live in the gray twilight that knows neither victory nor defeat."
- Theodore Roosevelt,
speech before the Hamilton Club, Chicago, April 10, 1899