Depends on your purpose
If you'll be racing, you'll want as smooth a finish as possible & stormjib's suggestion of wet sanding might be the best option.BUT...if you're just hanging out having fun, and even close to being the wimp that I am, using a good rotary sander should work fine. Now, I'll admit, the bottom on Salacia is far from being as smooth as can be but I SCREAM past other boats all the time so it can't really affect your speed too much.One other important thing to note: If you don't know what kind of bottom paint is on there now, you'll have to completely remove the old stuff before applying new. Some paints don't react well together & the new stuff will flake off in no time. You can remove it by sanding (the hard, cheap way) or by stripping (not as hard, but more expensive). A good stripper like Jasco (you can get it at Home Depot & the like) will work well but it's pretty toxic. If you're sanding, most yards require it to be the kind that a vacuum can attach to so it won't harm the environment (this is nasty stuff, remember).Either way, the entire procedure, from stripping to painting, you'll need some good protective gear, like jumpsuits, respirators, goggles, gloves & boots. There are a number of good books on maintenance that you can probably check out from your library to read up on it more. Good luck - it's the worst job in the world!LaDonna