The history of the German U-Boat War of 1939 through 1945 has never before been told in any great depth for various reasons.  One reason of course, is that this data was not readily released to the general public during the war for reasons of security.  Learn more about this historic event at https://sharkhunters.com/books/ and for information about Sharkhunters, the official history of the U-Boats, go to https://sharkhunters.com/
After the war the U-Bootfahrer were held in great hatred due to the heavily slanted propaganda during the war years that claimed that German U-Bootfahrer were raving Nazis; that they machine gunned helpless men in the water – all absolutely false, but propaganda is a valuable weapon during time of war.