I have to second the Tide pens. Although I have noticed two things about them. They aren't great for huge stains.. and depending on the substance that is on you.. when the Tide pen (which smells like laundry detergent) mixes with the stain, there is a chance it will smell like the most...
I used to surf when I grew up on the Jersey Shore. I now live in SF and it's been a long while. Out of curiosity, did you buy a long board or a short board.