Been looking for good locations myself. I can legally fly to 300' from my driveway (with clearance from SJC) so it's good to practice. I've flown from the beaches around Davenport (North of Santa Cruz). There isn't anything saying not to, and B4UFLY says it's ok. California state parks don't officially restrict drones.
Unmanned Aircraft System (Drones) in State Parks But if you look around most of the State Parks around our area specifically say no drones. (Ano Nuevo, Henry Coe, Henry Cowell, Natural Bridges, Half Moon Bay, etc) . Checking the parks down the coast and I don't see any restrictions around Pismo area. I flew at Shell Beach the first weekend I had my drone, but of course I was pretty much too afraid to actually get out over the water. I don't see any restrictions at Morro Bay either. Hollister Hills State Vehicular Recreation Area is near you and I don't see any restrictions on flying there. Other than Shell Beach and Davenport, most of these are guesses so take it with a grain of salt?