This is a video taken by someone last month of some windsurfers getting after it at Ocean Beach. Ocean Beach is the main beach on the West Side of San Francisco. It's about 4 miles long and a couple hundred yards wide on low tide. It's fairly unusual to find good windsurfing conditions, or even conditions that are windsurf-able out there. The predominant winds are directly onshore and the water conditions, as you can see, are pretty friggin' gnarly.
Ocean Beach is considered an advanced surf spot. Usually, you'll have to paddle through 10-20 lines of white water to get to the break. When you get there, the waves are extremely peaky. It's hard to position yourself and you normally are paddling to different positions the whole time you are out. I've been crushed by a couple of waves out there, so I can attest to the power and speed of the wave there.
The long and short of it is that windsurfing this spot is NOT for the faint of heart. You had better have skills, courage, and a hunger to challenge yourself to go after it here. Props to the sailors in this video. Ryan from South Africa (silver naish) and Vincent from France (Yellow MS) are Crissy regulars who definitely have a reputation of being a couple of the braver guys in my neighborhood.