I don’t think I could get away with dive decorating the camper, my home was already that way when we got married and she puts up with it. 90% of the pictures on the wall are underwater, scuba tank and fish pillows and the downstairs bath looks like you are standing on a pebble bottom looking out at the ocean, the towel hook and lights are octopus’s and I’m still painting fish and divers on the walls :)
A rinse kit or solar shower would be easier and a lot cheaper than taping into the RV plumbing which is all buried in the walls. My fathers old camper pre-dated inside baths, he used a black jug on the roof with a hose and had made a folding shower curtain rod. Of course a shower curtain at a breezy beach location might be a problem :(
I had made a drying rack out of a section of wire shelf that hung on the ladder but things blew off, luckily it was the soft stuff and not camera gear! I’m thinking a shopping basket or milk crate would work better with maybe some PVC tubing to keep the boots in the best drying position.