Jay,
Any automotive paint or fiberglass supply will have 2000 grit. However I assure you you do not want to sand your 20' boat with 2000. I've used 600 and then polished gelcoat with a buffer and trust me the 600 sanding scratches polish out. Leaving 2000 grit scratches on the hull will only lead to quicker dulling and discoloring. There's no doubt that a 2000 finish will have a shine and be smooth but its still not a polished or sealed surface.


Mel,
Lacquer paint is not legal anymore. It's been outlawed because of its VOC's. The only people that can get it are people that can prove that it's being used for restoration purposes. Were talking classic cars.

All cars are painted with urethane based paints. Most cars are two stage paint. The base coat is the color and dries to a semi gloss finish. The clearcoat is sprayed over that for durability and shine. A friend of mine has a body shop. I can assure you that every car he paints gets wet sanded and buffed. He uses 1000 grit then a aggressive compound then a foam pad with glazing compound.

I do touch-up paint repair for high end car dealers. I use 2000 to remove very fine scratches that are in the clearcoat. Then those are polished with a foam pad. If you want to test your theory that 2000 polishes try it on your car and let me know what happens.

I really don't see the need to use 2000 for any other reason.

So, you still want to wet sand with these grits?, then I would do it this way, Go to Wally Mart and buy a jitter bug air sander. Find a capable air source and put your thousands grit paper on that. That way you can run water and let the machine do the work.