The drywall sander, with the screen, and keeping it wet, cuts through bottom paint like no sandpaper I've ever used. No dust, excellent results, and a lot less work than an orbital sander. The big difference is the direction you sand. Instead of sanding longitudinal on the hull, you sand from the waterline toward the keel. It's a lot less strenuous and you're able to get into those tight curves where the keep meets the hull. Of course, some areas will obviously have to be done by hand because of tight access.