Take a look at this cool NOAA video of 1952 commercial shipwreck in San Francisco Bay near the Golden Gate. The depths are shown in color gradations and the wreck's location on the chart is shown in a clever translucent animation. More then anything, this short video demonstrates the vast area of sea bottom in a large feature like San Francisco Bay. You could easily lose a whole 1849 ship full of Gold Rush nuggets down there. . . . .hey, come to think of it, anybody have a side scan sonar rig we could borrow for a few weeks?