Having sailed SF Bay, I can identify Steve's trials and tribulations. It's a challenging place to windsurf, let alone kite. The main problems are shifting wind and current. At least on a windsurfer, you can usually slog back in, or de-power your sail when the wind suddenly changes.

My friend Mark was out several miles when the wind died late in the afternoon. The current carried him to the Alameda side where he came ashore at night. Wandering around in his wetsuit, he got a homeowner to open the door and call for a ride. Now he carries a marine radio.