SS, I did my 21' Starcraft with the Rhinolining roll in bed liner. It's been holding up well, mine has a wood floor in it, but I'll bet it would adhere to fiberglass just as well. It took a gallon to do it and in some spots I rolled 2 applications, where I walk a lot. Blue cats still make it real slick when they roll around in the bottom of the boat. The local auto parts store only had black, but I painted it once it had cured with deck and porch paint.
PS: In the summer when you're in shorts fishing, it will still take the hide off of knees when you slip.