I tried one of those polymer coatings for boats. Used "NewGlass2". My yellow hull hadn't been touched in at least seven years. The product advises you use something like "Softscurb" from the supermarket to remove any oxidation that would come off on your finger by touching the hull. Wash and rinse well. Let dry any oxidation remaining should be gone over with some wet or dry sandpaper wrapped around a wet sponge with plenty of water. Once that is done and rinsed use the applicator supplied and apply just wipe on at least five coats of the polymer.Don't sand too much getting off the oxidation since the polymer will just draw the remaining oxidation down into the porous gelcoat as it is applied. My yellow hull was cleaned as above. I then applied the polymer with the supplied squeegee. It takes about ten minutes to coat the hull of a 17. After the first coat go back to the starting place and start recoating again. It drys quickly. Try not to apply so much that you get drips. They are hard to remove without cleaning off all the polymer. Here the strakes in the hull are an advantage since the applicator just covers one width of a strake so one stroke applies a very nice application. Overlap slightly where you stopped your last stroke to blend in the subsequent strokes. It goes very quickly and is very satisfying to watch the deeeep luster build up right before your eyes. My hull looks just like the day I finished applying the polymer and that was three years ago. It took me about an hour or so to put on seven coats. I am not affiliated with this company, just a happy customer. Their number is 800-785-7675. Nice folks. One quart will do about four monty 17's or one Monty 4 times over the years. It is very easy to do the hull this way. No buffing. Check the Monty photo site under "AS-IS" to see a comparison of the starboard and port sides of the hull, half way though doing the hull. This is actually a fun process. Fair winds, Tom B