PH has to be the focal point of attack since that was where the main US fleet was based. Attacking any other base would be a gamey move in Pbem but against the AI you can do whatever you want.
No, I disagree. Unlikely strategy, but not gamey. Of course, in a PBEM game, with non historical 1st move, the subs might not be in Manila, if the Allied decided to surge them out, after intercepting the last part of the 13 part message. (Manila had a purple machine)
So, if in a non historical 1st move, no house rule restricts port attacks to Pearl, the allied side might do well to surge his subs on turn 1. Is this possible?
Appear at places to which he must hasten; move swiftly where he does not expect you.