I tried to say: It takes a move to launch a Ftr from a Island (Hawai to EPO is one move), but it takes no move to launch a Ftr from a carrier.
For example: HAW-EPO (1), EPO-NPO(2), NPO-EJS(3), EJS-NPO/BRY(4). A Ftr from the island of Hawai could attack EJS and land on a carrier in for example NPO or in BRY, if it belongs to your side.
If they start from a carrier in EPO, it would look like this: EPO-NPO(1), NPO-EJS(2), EJS-NPO(3), NPO-EPO(4). So they could land on a carrier in EPO, but not on the island of Hawai.
And, well, you’ve just shown me a mistake of mine. The two Ftrs from WUS can engage EJS and land on your carrier that would be in EJS after the battle. If your carrier is sunk, your Ftrs won’t die instantly, but at the end of your Non Combat Move. They will participate till the end of the battle, but crash afterwards. So in this case I’d advise you to take your planes from WUS as casulties first and not the Carrier.
Only defending planes can retreat 1 move to a landzone/island, if their carrier is sunk in battle and they survive.