In order to properly repair your boat's bottom you will need to get it dry first. Then using a grinder or belt sander with approx 60-80 grit paper grind the areas where the fiberglass matting is exposed (or worn). Visit your nearest Boaters World or West Marine store and pick up some fiberglass matting and resin...West Marine on Mercer in Seattle has a big fiberglass repair department and should have atleast one person up to speed on what you need. Layer the fiberglass matting on the damaged areas until the area is built up to the level you want. Sand the area again to smooth it out to the contour desired. To coat the whole bottom you may want to explore epoxy coatings. The coating is like painting. Your boat most likely has a gelcoat paint job on the bottom now. Since the bottom of the boat is already fiberglass there is really no need to try to coat the whole bottom unless it is damaged. There are also Teflon-like sheets that some attach to the bottom of drift boats to prevent damage.