Acme Mapper... Great Free Topo Maps and Images.

http://mapper.acme.com/?lat=38.016219&long=-122.50967&scale=14&theme=Topo&width=4&height=3&dot=Yes

If you zoom in to the 4 m/p level... you get more detailed bottom contours.  This thing is great.

Nice.  It even gives GPS coordinates.  Perhaps, I can use it with my new Christmas present --- a handheld GPS