Jeune Bros. on Johnson street has the thread you need. UV resistant. Not sure of the name, but they sell spools at the counter. The Singer sewing repair store across from Uptown has industrial spools avialable too.

After many attempts, and much practice, I finally got up on foil, albeit for ten seconds...but pretty exhilarating. I think I am hooked. This was all to practice graduating from the 140L inflatable to the 82L Ginxu XT...Such a difference!