Nink, not to pour it on, but on the SF bay note, I have to add in a few more comments. First, there are pockets of insanely large currents (remember how no one could escape from Alcatraz except in the movies?). If you were to fall off a jet ski, you may be forever separated from it and unable to make it ashore unless you are Michael Phelps or Sean Connery. Also, sharks enjoy cold water...humans do not enjoy sharks or cold water.
Either way, your fiancee shouldn't need a car...she can always invest in a sweet mountain bike, a pair of snow skis, and a wine hutch.