Maybe fabricating a rack or box on the back of the RV that is welded to the frame (Not the bumper) that would give you a place to put the boat. While the previous solution of under the TT and the frame brackets would work also, I would be concerned with the clearance underneath along with the ease of getting it out and putting it away for the ride home. Seems like the back of the RV would provide the same solution without being so difficult to load/unload while eliminating any risk of tire treads beating it up or pot holes, speed bumps causing a problem.
Just my 2 cents. Good Luck in solving your problem.:)
