The easily accessible Bayside Coast has a popular windsurfing location at the perenially windy Coyote Point Recreation Area, just south of San Francisco Airport, as well as Mountain View and several Silicon Valley parks with lakes. The Pacific Coast offers spectacular wave-surfing possibilities at Waddell Bluff State Beach and elsewhere. Check the local phone directory for equipment rentals.
The Bayside coast between San Francisco Airport and Coyote Point is one of the most popular places in the Bay Area for windsurfing. The relatively flat surface of the Bay, combined with strong ocean winds sweeping in through a gap in the hills (the same winds that drive San Francisco Giants outfielders crazy) make for fast, exciting rides.