Nate, how do you know about Tam? Have you been there? Don't be too dismissive of Tam just because it is only soarable 10 or 15% of the time; I have seen hotshot mountain pilots there many times, and they certainly weren't there for the great soaring. Like Stig's photo, the place is drop-dead gorgeous.
Sometimes even a benign and predictable site like Tam will surprise you. I had heard vague rumors about a convergence that sometimes set up over the beach, but no one I knew had ever encountered it or knew much about it. Normally, once you were over the beach you were in flat air and you were going down, period. Until one special day when I lucked out.
The day was flat, there was no significant lift anywere, so with nothing better to do I headed to the beach earlier than usual, arriving with 600 feet to spare. Suddenly my vario went off! The lift was very weak, and seemed to be concentrated in a long band parallel to the beach and about 500 yards long. I milked it for all it was worth and 10 minutes later I was back at 1900 feet, level with launch! I thought I was dreaming.
I knew I would never experience this again, so I pointed my nose towards Japan and headed straight out to sea. The lift band extended over the water for several hundred yards, and I went about 1/4 mile losing only about 200 feet. When I came back to the beach, arriving with about 800 feet, the lift was gone. A magical door had opened for just a few minutes, and I was incredibly lucky to be there.