I’ve played CLASSIC  Axis and Allies for years and don’t know how I never ran into this stupid problem, but it seems a couple of rule quirks result in the Submarine piece being a real waste of IPC’s in ALL cases.  Please clarify if I am wrong. 
So, as I understand it, upon initial placement after purchase a sub is considered surfaced.  Also, at the end of each turn, the sub is considered to have resurfaced.  Add to this condition the fact that Subs CANNOT shoot at planes.  So, enemy planes can attack subs at will, and subs can never shoot back.  They can only submerge after the initial attack by enemy planes.    Nevermind the subs “sneak attack” except when a destroyer is present, apparently this point is moot where PLANES are involved.  The sub can’t shoot first, can’t return fire, can’t shoot at all!  Why would any fool ever go at subs with any seapower at all–- just use planes, right???
Lets say Germany buys 4 subs early in the game.  They are placed at the end of the turn in one of two places, the sea zones opposite the two (original) factories.  The U.K., a major AIR power, of course can attack these subs in either spot with ease with fighters and bombers, fearing no counterattack.  Land in Gibralter or whatever.  Lets say there’s 3 hits.  The subs can’t shoot back, never got to attack, nope, they just sink.  The last remaining sub decides wisely to submerge.  Is it safe?  No! Because after Japan’s turn, the USA gets to hit this once-again-automatically-resurfaced Submarine with ITS planes, fearing no counterattack.  Lets say it misses, and the sub gets to submerge again.  But guess what, the rules say it resurfaces at the end of the turn again, so now RUSSIA gets to attack it with ITS planes.  WTF???

I’ve discussed this with the Axis & Allies guys on the phone # listed at the end of the rules.
They confirm this idiocy.  Why would anyone ever buy subs with rules like this?  You could build a factory way far away from all enemies with the express purpose of making subs but once they left to go be useful somewhere then any that are ever left after the attack are sitting ducks (read: definitely going to be destroyed) until the next turn.  Please tell me its not so.  At this writing a 9 hours and counting game just got folded up because Germany’s strategy had relied upon subs to protect its coast.  Upon realization of these rule-quirks, the waste of money to get super-subs and the purchase of like 9 of them was considered to be such a waste of money that  I foreited the game rather than see them all sunk and watch W Europe get invaded.  I’m not sure I’ll ever play this game again now that my favorite peice has been rendered pointless.  Please help!