If you want to really make it look pretty, and help with the elbow-grease, a Dremmel or similar tool with a grinding bit will remove the cracked gelcoat quickly. If you don't have mold release, a sheet of mylar (found in the gelcoat repair kits) works just as well. I've used waxed paper, but the mylar (when mold release isn't available) works better. I extend the new gelcoat about 1/2" past the repair area, and feather sand it to blend and smooth when it's done.

If you're working on the non-skid area, you can get a similar texture by spraying on the gelcoat and then gently blowing sugar on the surface before applying the mold release. When all is cured, just hose off the surface. The mold release and the sugar will be removed, leaving a non-skid surface. They use this on surfboards a lot ("sugar deck")