lived in that area for 6 years. learnt to dive there. all the diving is in monterey, about 2 hours south of SF. excellent diving, cold all year around though, roughly 9/10C. kelp forest are incredible. viz not so good, anything over 5m is exceptional. teh shop i learnt to dive with was called Diver Dan's, it's in santa clara at the bottom of silicon valley, an hour north of monterey. if you contact them they may be able to help you.
also, while i don't like to promote another forum, and i don't like a lot of what is recommended there,
www.scubaboard.com has a nor cal section, where you can post a message for some of the local divers and they will help you out.