Hi Bubblehead1980 Kreigsmarine inteligence was very good and the hydraphones on the Uboat was also very good so when a Uboat picked up convoy signals 20-40 kms away he would act as convoy keeper when in visual contact vectoring in more uboats from the dispersed Wolfpack Recce line.
the Allies had cracked the enigma code so they could see due to uboat transmissions being decoded that a Uboat wolfpack of say 8-15 Uboats closing on the Convoy.
The Allies would rush Convoy reinforcements to that convoy striping a Convoy of one or two escorts if that Convoy was well past the Rockall Banks on its last 12-24 hours from liverpool or escorts would sail from Belfast or Liverpool or Reykjavik Iceland
to beef up the Escort Screen or in bad weather six merchants are scattered at the stern of convoy a corvet rounds them up 8-12kms behind convoy where the Uboat convoy contact keeper is shadowing convoy on the surface.
So the potential for 1 v 1 Escort against a Uboat would be common Uboat closing on Convoy on the surface at 10knts escort closing on same Convoy 12-20knts if the escort had HUF/DUF High-Frequency-direction-finding
the escort would see the Uboat before the Uboat saw him
https://en.wikipedia.org/wiki/High-f...ection_finding
Convoy SC-42 good Read The Canadian escort group EG.24 (LtCdr Hibbard) consisting of the destroyer HMCS Skeena and the three corvettes HMCS Kenogami, HMCS Alberni and HMCS Orillia.
but look how many reinforcements Convoy SC-42 gets
https://uboat.net/ops/convoys/convoys.php?convoy=SC-42
World at War Wolfpacks a very good watch enjoy one hour documentary
https://www.dailymotion.com/video/x3p7bjc