Porta bote is a great boat for RVing. It unfolds to a full sized boat.
They fold to about 4 inches deep and come in 8, 10, 12 and 14 foot lengths. The 10 and 12 footers are probably best, as the 14 footer gets pretty heavy and hard to handle. I can actually lift the folded 12 footer by myself, but having two people makes it easier.
They have mounts to mount on the side of your travel trailer. We did this three years ago and have had no problems. The total width of the TT plus the folded boat is still under the legal width limit. Some people also mount underneath the trailer, and some put on top of their tow vehicle.
We take ours everwhere we go, and enjoy fishing and boating nearly everywhere we camp. A small 35 lb thrust trolling motor is all that's needed to propel us around.
I have posted photos and detailed instructions for side mounting on this forum. If you Read the entire 2 page thread you will find the detailed instructions.