The sponsons look beautiful. how are you going to finish them? light fiberglass - looks hard with the slightly rounded edges. Spar Varnish? something clear I hope, cuz you dont wanna cover up the purdy wood.
I do hardwood floors by trade, so I have access to all of the stain and finish I could ever need. I'm going to pop the grain up and stain it first, Then 1-2 coats of Oil-based Polyurethane and topcoat with about 4-5 coats of a 2-part waterbased commercial grade polyurethane. I think 6-7 coats should probably be enough to make the hull and sponsons water-tight. Fiberglass is too much work, and Epoxy finishing resin doesnt bond with wood stain very well - it fisheyes really bad.
Final sheen will be a satin sheen - I am using waterbased satin because in my workings with it at work, it makes a VERY slick surface. Far slicker than a gloss (epoxy sets as a gloss) so I am hoping this will help it get a little more speed.
I made a stand for it - this should make it easier to set it up and get it started when I go run it.