Leather would likely
work, though it's quick to get wet, & retains moisture for a long time. Which is important if your
davits are
aluminum, & aren't anodized, or otherwise coated.
You could also simply do some nice knotwork on the
davits, using anything from 3mm cord, to 10mm braid, or line cover (sans core). A pattern of half hitches with the cordage going fully around each davit arm before throwing in another hitch would work. And you could alternate the direction of the hitches so as to get a straight vertical line of knots... The type of
knot, & variations of them are endless. And line past the age of being good for serious purposes works well after a quick trip through the
washing machine.
You could also stitch
canvas or neoprene in place over the areas in question. And on, & on.