Lets hope they do have other subs this time, SH3 was kinda let down badly by that. At the moment the DEvs have said that AI subs are desirable but not essential, so if time allows they hope to include them. If they do lets hope they are smart enough to conduct submerged attacks etc.
You know there was one instance during WW2, where a British V class sub sunk a German IXD2 Uboat with a spread of torpedos while both vessels were submerged - the only instance of this ever happening in all of naval history.
