I have finished transcribing Volume II of the British "The War at Sea", which covers much of the period of US involvement in the Atlantic Battle. Interesting to get the perspective on things from the view of the British.
As with the other documents I have transcribed, this one can be found on the HyperWar web site. Here's the link:
I am now working on the Operations Evaluation Group Report 51 "Antisubmarine Warfare in World War II", which contains a significant amount of material on submarine encounters with the Convoys, strategies, technical developments, etc.