Slitherine

I play the BJR mod and the vanilla game in PBEM. And with vanilla game, no matter the tactic i use, subs are a waste of PP for germany. Allies doesn't even have to escort convoys, they just keep fleet between UK and USA and when a sub or more than one attacks a convoy, they maul it in 3-4 attacks.

Even if i sink the convoy attacking with 4 subs, i end up losing a sub (60PP) so i end up losing more than i kill.

is there any tactic? in BJR mod obviously it's all another thing and subs are deadly till '42.

position some german units adj to ports early on ...allies have to send the royal navy to be able to cover a possible invasion...early on they have 3 up there (unless more come from the med.)...they can't be everywhere at once...send subs to the south atlantic...allies will try to protect the northern convoy at all costs since it is worth so much...

Sub Warfare can be done in 2 ways, by confrontation or by sneaking. Confronation means you have so many or strong Subs that you can deal with incoming navy and engage them in combat. This is quite unusual and occurs if you have a big tech lead so much more modern units.

More commonly is to strike with Subs away from the center of map, The Atlantic is large so in order to cover NW, S and SW edges of map Allies need to split up their naval forces while Axis can mass up all Subs in one place.

Battleships do not gain so much tech in anti sub warfare which means if you invest in early Sub research then Allies are forced to build destroyers to keep up.

If you have only 1-3 Subs then confrontation is quite impossible, you need a large groupf of Subs to be able to provoke and strike near the center of map.
Subs were made more useful in 1.12 so if you have previous version update to latest patch.