back with my 96 xp, it was easy.. i didn't give a dam
I actually care about dock rash on my new(er) ski now, so i'm more careful. and shockingly my new ski has even less under the hood storage than my xp did, so bumpers are out of the question.
but seriously, the only thing you can really do is tie the ski carefully and correctly, to avoid it drifting under a dock.
Generally speaking this means positioning the ski near a post and tying it off on the front (I use the steering column) and the rear (I use the grab bar) and tying them rather snugly to avoid it wiggling itself under the dock. Obviously keeping the tide and current in mind is a factor as well. Most of the time, if there is an actual current, its easy, just tie it downstream of the current and let the water naturally push it away from the dock. But usually my dock rash comes from stray boat wakes that crop up and push things around. Over the years of riding it's become second nature to avoid the end of the dock (waves pushing me back into the wood, etc)
Also, you could always do what my brother does, he ties his ski off onto MY ski, and climbs over my ski to get to his, he never gets dock rash that way... (prick) however, I can't blame him, his ski is an 04 with ZERO scratches and he wants to keep it that way