Its part of rafting, as in, part of rafting is coming down to your boat in the morning and unloading it, dragging it up on the beach and delaying the crew so you can patch.
Preventative patches on an area that will constantly have abrasion are never a bad idea. Right now it is aluminum marks. Before long it will start pitting out and wearing thin, especially when grit falls in there and starts rubbing. Patch and forget about it.
I like the clear bra idea!!!