Bruce - doesn't look like a Scorpion to your left! (Not wanting Scorpion owners to get a bad name!
Also, I think I would have tied up alongside the main pontoon rather than rafting as, whenever you raft, you are leaving yourself at the mercy of the boat you are rafted to if s/he leaves before you do! It probably would have been possible to motor in, put someone ashore and then use ropes to pull Farfetched round to lie alongside the main pontoon. At least then there is less likelihood of someone messing with your ropes!
Blue Ice has several thicknesses of hypalon around the area that the tube fixes to the nose so that would seem to be the way to go!