Yes, Kiwi Grip is thick and is applied with a textured roller. It will cover up the original diamond pattern in the Gelcoat. For those of us who have damage to that non-skid this is the best option. It is easy to apply, looks nice, has a softer feel under foot than other non-skids, and easy to repair or recoat in the future. It is also water based. The best prep is to sand the Gelcoat non skid near flat (but it does not have to be perfect), clean/de-wax with acetone/laquer thinner/denatured alcohol and prime, then apply Kiwi Grip. If the tread pattern in the Gelcoat is not damaged and you want to preserve it then Brightsides with the non-skid additive is your best bet. You cannot sand the Gelcoat, but you must clean it very good with a deck scrub followed by acetone and a stiff brush (natural bristle). The acetone will soften up the non-skid, so do this very shortly before Primer and not in direct sunlight if you can avoid it. Use Interlux Pre-Kote primer (NOT Prime-Kote, that is for Perfection 2 part paint). Two coats is sufficient. Contrary to a previous post, just a difference of opinion, I would fine foam roller... You don't want the primer to lay on too thick. Your non-skid pattern should still come through just fine. Two coats should be fine, but with a fine foam roller 3 would be ok I think. Prime Kote dries very fast in good weather, all coats can be re-coated within 30 minutes at or above 70 degrees. Do let the last coat dry overnight. Brightsides in a one shot deal when using the non-skid additive. When Brightsides cures the gloss rises to the top and becomes the hardest surface, but your gloss will be cut down by the non-skid additive considerably. Brightsides cannot be re-coated without sanding, this is true of all one part polyurethanes. Using a 1/4" nap roller you should get excellent coverage and your non-skid pattern will still be good. I'd have to check the tech specs but I believe you do not want to thin Brighsides when doing Non-skid decks. You will be amazed at how far just one quart will cover! Don't buy 2 unless you are sure you'll need it! BTW, our host, SBO has the best prices I can find on Interlux paints, fast shipping too.