Perspective view looking to the southeast over entrance to San Francisco Bay.

Perspective view looking to the southeast over entrance to San Francisco Bay. Golden Gate Bridge is to left (east) of this view. The large sand-wave field lies within Golden Gate channel, and formed from sediment transported out of the Bay by strong tidal currents. Profile A–A’ shows that the larger bedforms can reach heights of over 7 m and are asymmetrical with steeper sides towards the open coast. A smaller field of sand waves to south near Baker Beach shows the opposite symmetry (steep sides toward the Bay) indicating that the strongest tidal currents in that local area are directed eastward.