[UnderseaLcpl]

Perhaps I should be more specific.
Starting in about May of 1940 I noticed AM97 was a great place (logically) to catch convoys.
Once I got fairly close to one I would get a contact report even though my boat could not see them.
I assumed these are supplied by B-Dienst decrypts.
However, seemingly immediately after I received the reports the convoy changes course. Ultimately I get stuck In a desperate chase with frequent hydrophone checks to get in front of it.

From the replies so far I gather there is no rerouting of convoys and it is just my bad luck combined with frequent convoy course alterations.

If this is incorrect and some other mechanism is at work here it is doing a great job of simulating the work of Bletchley Park's cryptanalysts and staff. Bravo GWX!

BTW HW3 I am almost positive that radio messages do call down the thunder. The past 4-5 convoys I have attacked used up all my torpedoes and as a final service I supplied a contact report, only to be beset by 4-6 Escort vessels after I sank the convoy escorts. In fact I would suspect that DD's that are damaged but not sunk can return to nearby ports and then return to pursue you as I always seem to be attacked by escorts of the same type as ships I damaged but did not destroy several hours later.

Any additional insight is appreciated!