I managed to bottom paint my boat while it was on the trailer. I got the areas where the boat rests on the bunks by making a bracket with 4x4s and 2x4s. The brace fit under the hull of the boat between the bunks. It was tall enough so that I could barely fit it under the hull when I had the tounge of the trailer as low as I could get it. Once I had the bracket in place I jacked the tounge of the trailer up and I lifted the boat up off the bunks about 2 inches (barely enough to get the paint brush in). The boat rested on the bracket and the bow roller (actuall a wooden block that I put on the trailer). Worked good enough to paint the boat while it was on the trailer. After I had that area painted I lowered the boat back onto the trailer by jacking the tounge back down on the trailer. Today I just finished the last coat of bottom paint (finally got a two day window to do my painting). Boat goes in the water on Friday!