It's not fun doing all that sanding. There's way more gel coat than you think!
3M makes a grip tape for steps that works pretty awesome. It's rubbery and not super abrasive. I stuck some on my boat a few years ago and it's held up very well. The stuff used on skateboard decks is sandpaper and pretty harsh on your gear.
I've thought about sanding all the gelcoat off and painting my hulls, I was planning on just using the 3M grip tape to replace all of the non-skid.
