I was interested to see this site but horrified to see a reference to U-571.
I am a volunteer guide at Bletchley Park (writing on my own account) and I also lecture about WWII naval history.
Surely you are aware that the film U-571 generated great hurt on this side of the Atlantic because it was felt that the USA (well Hollywood anyway) was tying pinch the kudos of the first capture. This was of course done by the Royal Navy from U-110 in May 1941, before the USA had entered the war. Eventually the film company added a sort of apology to the end of the DVD.
The USN has a perfectly good example for you to use, if you choose, and that is U-505 captured off the Cape Verde Islands by TG 22.3 (USS Guadalcanal + 5 DD).
There was of course a U-571 which made 11 war patrols between 1941 and 1944 when it was sunk by an Australian Sunderland off Ireland.
I wish your site well but care is needed when choosing specimen identities!
No offense was meant. It's a movie. It's a fiction movie. It's a fiction movie that has brought the basic Enigma story to thousands of people worldwide who, otherwise, would have no idea about our obsession.