Built, tested, and designed for the Pacific Northwest in Newport, Oregon!

SURFBOARD FINISHES

LONGBOARDS
Nearly all longboards, guns, and funshapes have a gloss resin coating on their surface.  Gloss resin is the most effective way to seal the fiberglass surface and provides the greatest durability.  There is some weight added in glossing, so it is not normally used in shorboards or high-performance  mid-length boards. 
My standard finish is sanded gloss (400 grit wet-sanded) on the bottom and lower rail, and polished upper rail that blends into the bottom finish.  I attempt to get the cleanest possible application of gloss resin on the deck, then not sand it at all.  The advantage to you is lower cost (polishing is a costly step) and a stronger deck.  Unless the board becomes a wall-hanger, you're going to cover the deck in wax, so why pay for polishing?


SHORTBOARDS
Generally, shortboards will not have a gloss resin coating.  Most are sold with a sanded finish.  The un-glossed fiberglass is subject to water intrusion through the many tiny pores on its surface.  That may not matter to a pro or someone who buys surfboards frequently.  But for the rest of us who pay full price and want our board to last longer, there are ways to seal the fiberglass without adding significant weight.
I seal the entire surface of each shortboard with three coats of clear acrylic.  
The cured surface is then hand-rubbed to a matte finish.