I've been advised to give my stern bumper a coat of inflatable boat paint once a year or so to ensure longevity. Should this be paint for PVC or Hypalon boats? Do we know the material the stern bumper is made out of?
I used a water-based rubber paint formulation that was recommended both hypalon and PVC. It works well. In general, PVC is the more difficult material to get something to stick to because the plasticizers that are used to make it flexible tend to coat the surface with an "oily" layer.
Years ago, when I owned a Santorin, I asked the sailmaker (for canvas work) to make a skirt of white vinyl around the bumper with an elastic tensioning cord. It worked quite well and although I renewed last year the bumper on my SM, I will ask the canvas man in Combarro where my boat is now to give me a quotation for such a skirt for my old bumper.