Paint above deck and below?

[Destroyer]

For a boat on a trailer it's simple.. Power wash the entire hull, then tie a line from the back of your boat to a tree, release all tie downs on the boat, back off your winch cable about 1 foot, hook up your trailer and gently pull the trailer forward so the boat moves that one foot backwards. Now you can clean the areas under the rollers easily with the powerwasher. When done, just winch her forward that one foot and you're finished.

To remove oil scum, absolutely the very best product, bar none, is MaryKate On & OFF. Just MAKE SURE that you wear rubber gloves and eye protection and DO NOT use it indoors. The stuff contains some very powerful chemicals that remove the scum instantly. You just apply it with a sponge.... wipe on, hose off..done.

if you are going to remove paint, I know there are countless chemical products out there that will remove paint, but really, the absolutely easiest and quickest way is to hire a company to soda blast it. It's safe, clean, easy and the hours or days of your time that you will save will more than pay for it. When they are finished you'll have a sparkling white hull ready for polish