M_Boats: gelcoat repair

I've lost gelcoat from sections of my hull below the waterline: A section about the size of a stick of gum near the bow, and one a little bigger than a silver dollar on the front of the stub-keel. I'm no D-I-Y'er . . . I've never tried gelcoat repair. Am I safe using epoxy to fill the gouged sections (only millimeters deep, but exposing 'glass cloth), or should I repair it the way it was built? I don't really have the time or money to have this professionally done, but I don't want to make the situation worse with a sloppy home repair.