Dear Yanis,
I would recommend, at the very least, a stop at the maritime museum in San Francisco, especially the pier which is at the end of Hyde Street (where all the big ships are)
http://www.nps.gov/safr. There are a number of historic SF bay boats there. During the week and on Saturday, there is a lot going on down on the Pier. There is also the Arques School in Sausaulito, but they only allow visitors on Saturday, see their web page:
http://www.arqueschl.org/ for specifics. There are other places as well, there are historic World War II ships converted to museums, (one in Alameda and one in Richmond). A good hike is one out to Point Bonita Lighthouse (with good weather). Email me and we can discuss more specific things that you want to see:
ktkotz@uclink4.berkeley.edu