Provided you are okay with non-primitive materials:
warmed epoxy will penetrate wood pores and hold well against impact and water, depending on the kind of epoxy you use and the wood type. A common technique in speargun building is to warm the wood, then apply epoxy, and the pores will suck in the epoxy as it cools. I would check out this stuff:
http://neptonicsystems.com/epoxy.htmIt is not the easiest epoxy to work with, but it is very impact and UV resistant. I was doing a carp tournament in the Colorado river and got dragged downriver really quickly when they released water from the dam upstream. My speargun (whch was epoxy coated) got dragged against streambed gravel at 20+mph for a good while, and it came out with only some minor scratches. Now granted, this is a thick coating, as a speargun is unbending, so I'm not sure how well a thinner bendable coat would hold up under the same mistreatment.
What kind of wood are you using? The grain structure on different woods can make epoxy coating either easy or nightmarish. Either way, make sure you blow all the dust out of the pores with compressed air and wipe down with acetone beforehand.
As for the handle wrap, plumber's tape. It's used on polespear handles quite commonly, and provides great grip. Tennis racket grip tape could also work.