jap or british sub?

[Sonarman]

If there is a 1.6 I'd imagine it will just be to clear up outstanding bugs not to add whole new subs, remember the devs chose German U-Boats for the paid addon as they currently only have a small team and already had a lot of U-Boat assets to work on from SHIII. Adding Jap or British subs would be a whole different ball game. I'd imagine we have to wait for SH5 or at least another paid addon for that not a patch.