We have a boat that I plan to have for a long time so I try to take good care of it. We often drive on gravel roads with it and the BF Goodrich tires I have are really good at picking up rocks and throwing them. So to protect the hull of the boat I made some removable rock guards. I didn't like any of the manufactured ones because they left openings for some projectiles to get by and the ones I've see were all a bit wobbly.
I utilized the ends of the hitch to mount these guards. I used 2"x2" square tubing for the structural part and for the majority of the rock stopper I used Rock Solid Protective Guard. I added a fin like piece to the top of the guard that closely follows the contour of the body to close the gap that could have let some rocks by. The 2"x2" tubing is secure with a bolt so once it is tightened it does not move at all.
It only takes a minute to install or remove them.