I think there is a great opportunity to take advantage of all the great NOAA information out there provided by the government for free. With this I can use supervised learning with input from professionals and surfers using the site. I would gather professional input from the other surf forecasting sites out there and allow members to sign up and chart their own surf journals.
This would build surf journals for not just the popular spots like those you see on surfline but for anyspot a surfer desires. He could specify the closest booies and which area the secret spot was in and I would gather wind, tide, and swell information mostly to build a profile of the spot.
This blog post is actually being used as a landing page to gauge interest via a Google AdWords campaign. I will set this as the destination and hope people click through my ads. If so I know there are people interested in this idea as well.