Here are some cleaning tips I read.
Wash Your Boat
Wash your boat, or at least hose it off well — the last thing you want to do is grind dust and dirt into your gelcoat while cleaning! This will also take off the main layer of dirt and bird droppings so you have a better idea of what condition your boat is really in and the areas that may need extra work. To clean off all of Buck's shoe marks and other scuffs on the nonskid, wet a Mr. Clean Magic Eraser pad in your bucket of soapy water and use it to remove marks and stains. These work well, but never use them on smooth gelcoat or you'll remove all wax and shine and leave a noticeable faded spot. They're great, however, on rubber, plastic, and vinyl.
Clean The Canvas
Now's a good time to tackle the canvas while you still have your wash gear out. Wet down the canvas and run your deck brush over it to lift and remove loose dirt and bird droppings. Rinse well. Then use a mildew remover/cleaner spray to treat any sections where mildew has grown. Spray it directly on the mildew, scrub it in with a brush, then rinse well. If you live in a wet or humid climate, use a mildew treatment (such as Yacht Brite's Mold Away) that can be left on the canvas to prevent mildew from coming back. Spray the treatment lightly over the canvas and around the edges, and leave it on. It will keep mildew at bay for several months.
Cleaner Wax Touch-Up
The stains you'll find in smooth gelcoat can easily be removed with cleaner wax. This includes scuff marks from shoes, bird droppings, leaf stains, water streaks on vertical surfaces that didn't completely come off with the wash, and gray-water stains on horizontal surfaces. To remove these stains, squeeze a small amount of cleaner wax on a cotton rag, then rub it on and around the mark or stain until it comes off. Use a microfiber rag to wipe off the hazy wax residue. This is a great way to remove stains in between annual wax jobs. Not only are you keeping your boat looking good; you're also adding a bit of wax back to extend the life of your wax job.
You can also use cleaner wax to clean and polish your stainless steel. Use a waxy terrycloth rag to spread the wax over all the stainless steel, then use a clean microfiber rag to wipe it off. This will remove salt spray, rust, and dirt and will protect your stainless from the elements.
Exhaust stains can turn a white transom gray and make an otherwise clean boat look dirty. As you probably already know, exhaust stains don't always come off in the wash. Some spray cleaners are strong enough to remove exhaust stains; however, if they're strong enough for that job, then they're probably also strong enough to eventually strip that area of wax, only making it harder to clean the exhaust stains off over time. The best way to remove exhaust stains from gelcoat is to wax them off. This is something that can easily be done by hand with cleaner wax. Use a terrycloth rag to apply the wax, and wipe or rub it in until the exhaust stains are gone. Then use a microfiber rag to wipe the hazy wax residue off. If the exhaust stains cover a large area, you'll want to use several terrycloth rags as you go, so you're not rubbing the exhaust soot from the rag back onto another section of your boat. When you're finished, you'll be left with a clean, white surface, and it should be a little easier to wipe exhaust stains off next time because they'll be sitting on top of freshly waxed gelcoat.
Clean Vinyl, Rubber, And Plastic Surfaces
Clean vinyl seats with soap and water using a wet sponge or rag. Lightly use a Mr. Clean Magic Eraser pad to remove any stains or marks. Then use 303 Aerospace Protectant to protect them and give them a light sheen. 303 Aerospace Protectant sounds like something you might use to keep your rocket ship shiny, but it's actually intended for boats. It offers the same kind of UV protection as Armor All, but it packs a bit more of a punch and lasts longer. It can be used on vinyl seats, the rubber pontoons of your tender, plastics and plastic windows, leather, and the dashboard area of your helm station. It helps keep dark colored plastics, such as the helm station, from fading. Those little black specs of spider droppings on vinyl seats can also be removed this way. Spray with water or a multipurpose cleaner spray, let it soak in for 30 seconds, then wipe off.