Okay,... a question about casualties in unusual situations. What if a sea battle takes place between ONLY AIRCRAFT and ONLY SEA UNITS?
If I understand the rules correctly, in a sea battle, casualties are ONLY SEA UNITS (and in fact, in every type of battle this is case -- AIR battles = AIR casulaties, LAND battles = LAND casualties, or airfields). So what if there are no sea units on one side? What if a guy decided to take an entire wing of aircraft (say, 15 ftr, 5 bmb) against a combined force of air/sea units? After the air battle is over, say he still has 12 Ftr, 1 Bmb left and he wiped out CAP cover for the fleet.
1) In the sea battle, do the planes participate again even though he has NO sea units in the sea zone ... it's just planes against boats?
Yes. This would be true even if there were planes left that were friendly to the fleet.
2) If this is the case, how are the hits that the boat's score applied, since there are no enemy ships and the battle box will show hits against BOATS, not PLANES?
The ships would not fire at all during the Attack Sea Units units step, since there are no opposing sea units upon which to fire. The ships would have already fired at the enemy planes during the Attack Air Units step.