Fill a pail with hot water and add 1/4 cup of an all purpose cleaner. Use a scrub brush to remove dirt, grime and dried blood from fishing trips.
Use a degreaser to remove bird droppings from your fiberglass boat. Allow the degreaser to sit for a few moments, then scrub the soiled area with a scrub brush.
Remove stubborn fiberglass stains with 600-grit sandpaper. Wet the sandpaper and gently scrub the stain.
Apply wax to your fibgerlass boat to make the next cleaning easier.