A couple of squaddies and myself have tried landing PT boats in many situations... The most extreme was when one of us drove one (afk for quite a while) 3 sectors out into the middle of nowhere into friendly water... He got a ditch. We've tried beaching our boats at a friendly base (no cons in sector), stopping and towering out by a CV that wasn't under attack, etc... None of us has figured out how to get a "successful landing" message with the PT.
It's not a big deal, but it'd be good to know if it IS possible.