Ferries are magical boats that can take you to various ports around the bay. Some of them have reasonably priced, fully stocked bars.

Destination Operator(s)
Oakland Alameda/Oakland Ferry
Alameda Alameda Harbor FerryAlameda/Oakland Ferry
Larkspur Golden Gate Ferry
Angel Island (do you have to go through Tiburon? not sure) Blue and Gold Fleet
Tiburon Blue and Gold Fleet

Golden Gate Ferry, Blue and Gold Fleet

Vallejo Bay Link Ferry
Alcatraz Alcatraz Cruises