RE: recovery craft
This is similar to the scenario whenever anybody has gotten the idea to use a R/C boat as a recovery thing.
There's just not enough dexterity to hit the downed airplane in the right place and to keep it there while you power back to the shore. It gets VERRRY complicated VERRY fast while you start trying to figure out how to get the pieces.
Probably the best idea for a r/c retriever boat that I have seen is to use a conventional boat trailing a fishing line with a floating grapple. Drive around the downed plane, snag it with the grapple, and drag it back. No modifications required to the boat, and it works fairly well.
Rule number ONE for float flying: You need a boat-the man-carrying kind.
You might be able to get by with tennis balls on a string, long poles with hooks, r/c boat retrievers, or gravity wave generators, but ultimately (and that means at least half of the time) you will need to plunk your self into a man-carrying boat and row out to pick up the plane.