First "Hi" & "Welcome!!!"
The RO 150 is both exactly the right tool for the job and the a tool that can inflict untold damage to Glass Reinforced Plastic in the wrong hands.
Although the RO 150 with 24 grit or 40 grits are great bottom paint removal, they can cause deep groves in the gelcoat that will make for lots of fairing.... be very careful and "keep the sander moving!!!". These grits are fine for below the water line but must be used with great digression above the water line. Although the RO 150 has an edge guide, it is no edge tool for fine work. I would suggest you look at the DX 93 for edge work & the LS 130 linear sander for contours that mirror the motion of the hand. Using the DX 93 & the LS 130 in combination make's Bright work go quickly.
And as already mentioned, a vacuum needs to be attached to these sanders for this work. The RO 150 will if used properly work great for the larger areas, but if forced into small areas will due damage gouging inside & out side surfaces. In these areas, less is more... slow down & use detail sanders, or hand sand.
You did not mention the type of non-skid you will be placing on the surface. Of the three common the after market applications the glue down rubber mat covers up the most sins, but both the paint on with grit added or the not for the DIYer gelcoat methods require a very fair, no grit marks surface.
The Bristol sailboats although a quality boat, like all boats of this time frame were laid up by hand, thus they have many voids that lay just below the brittle surface. These you will have to fill but filling alone will not "hold" the surface together, and will crack back almost immediately though your freshly finished surface unless you apply multiple layers of fiberglass cloth to hold & rebuild a continuous surface. But of course these repairs will have to be faired.
Again "Welcome" and the greatest of success with your project.
jim
as if you didnt know already
