I have used this product (kiwigrip) on the last three boats we built/re-built. Its super easy to apply and holds up very well. Its a lot nicer (IMO) that just adding non-skid to paint. We made a youtube clip of how to apply it.
In full disclosure... My business is a distributor/retailer for it. We sell the non-skid additive for paint as well, but I will be using the kiwigrip on my Sea Craft decks.