@UnknownSoldier:
If I am doing a sea battle against a carrier, two transports, two fighters and a tac with 3 bombers and 2 subs, can my bombers retreat and leave the subs to sink the transports once the carrier is gone?
NO
All units must retreat at the same time.
However, subs can SUBMERGE individually, round by round.
Separate retreating is ONLY done with amphibious assaults, where the ground units coming off transports can never retreat, but everything else can retreat AT THE SAME TIME, together (and ground units to the same place)
What you can do with subs when your opponent has no destroyers, is leave them in the battle as long as possible by taking your air off first. Once you have only subs in the battle, that takes all their defending air out of the battle and you may be able to sink all their transports that way.
Subs are awesome, especially with the 6 IPC cost and double convoy damage. :-)
So hope that your opponent takes carrier hits with your bomber hits, and then lose your bombers first, if you want a good chance of sinking all the boats. Your opponent may be wise (depending on game situation) to take off his defending air if your bombers hit, and save the carriers, which are his only defense against the subs to protect not only themselves, but the transports.
A lot depends on whether his air has another safe landing place… But that’s how it works -
Let me know if anything is still unclear