Visiting Bay Area from UK between 7th and 17th

So I'm going to be heading over to the Bay Area soon and would like to do a bit of bouldering whilst I'm over there.

I'll be there over the course of 10 days, from the 7th to the 17th of March. Planning on bringing a crash mat with me but that's dependent on whether or not US Airlines decides to charge me an arm and a leg for the privilege.

My grandparents live in Marin, and somewhat irritatingly I won't have a car to get around with. Any local spots that anyone can recommend? Also it would be great if any locals are about to climb with.

I generally boulder between 6B and 7A. Which is like V4-6 I guess?