a little of topic ,but i do recall watching a tv documentary on about merchant convoys sailing across the atlantic too cardiff docks in wales i think :hmm: anyway the point i'm making is that this sailor said they knew when there was uboats in the area, that they could hear them
is this possible it would be cool too have this confrmed ,and that the escorts would leave them behind if they could not keep up with the convoy he said many slower ships where picked off this way