The National Oceanic and Atmospheric Administration has a series of excellent bay maps on the web. Although the NOAA cautions that the maps are not to be used for nautical navigation, they do show depth contours in considerable detail. This section shows the Bay Bridge where a South Korean vessel collided with the bridge, releasing an oil spill whose effects will likely be suffered for years.
The maps can be zoomed and dragged. In the following view I’ve zoomed in a little (but not nearly all the way) to show some of the detail that the maps contain.
As far as I can tell, the site does not as yet have a user-friendly overview page. You kind of have to go to a page — like this one for chart 18650 — and then back up a directory and hunt around — or you could just try entering contiguous numbers in the url. It’s worth the effort if you are planning on being out on the bay or if you have an interest in its shorelines.