USGS Bay Color Zoom Out

I Was a Strange Child…

with a huge imagination. I grew up on the Gulf Coast, and virtually lived at the beach. As a little kid I had this crazy desire to see the Gulf of Mexico without any water in it. I wanted to see the seafloor. I was conflicted, however, as I feared this would kill all of the sea life. I know, weird.

Well, turns out, I now can see the ocean bottom. (I would suggest turning the sound off. The music is horrid!)

Source: It’s Unbelievable To See What The World Would Look Like Without Oceans

Explore the San Francisco Bay Seafloor

I’m told the Bay Area overall is only an average of 6 feet deep because there was so much land mass pumped into the bay during the Gold Rush drilling efforts. Much of the Bay Area (Richardson Bay, for example) becomes mudflats at low tide. There are, of course, notable exceptions: under the Golden Gate Bridge is the deepest area of the entire bay: over 300 feet!

I find the maps/visualizations of the seafloor presented below fascinating. Clicking on any map will open a large image.

Hundreds of boats are at the bottom of the seafloor at the entrance to the San Francisco Bay. I was always puzzled as to why the ships would get to close to the rocky edges. I later learned that the sailing vessels had to tack from side to side to get into the Golden Gate against the raging currents when the tide is going out to sea. The bay water literally goes 6 miles out to sea before the tidal direction changes and brings that water back into the bay. You can often actually see it from the Headlands as the bay water can be a different color from the ocean water.

Depth is listed in meters with just over 3 feet per meter; so, the purple area is about 360 feet deep!
USGS Bay Color Zoom Out
I drew the Golden Gate as a semi-transparent gray line

USGS Bay Color Zoom In

USGS Bay Depth Marked
Depth Marked
USGS Bay Depth Marked Close Up
Depth Marked Zoomed In (Golden Gate Bridge seen as semi-transparent gray line)
Bay Entrance Facing South
Bay Entrance Facing South from the Headlands
North View from City
North View from City
Point Bonita
Bay Entrance by Point Bonita Lighthouse
Rodeo Cove
Rodeo Cove Just North of Point Bonita

Sources: Amazing sea floor maps reveal California’s offshore depths;

Fly Over the Seafloor: Central California — Bolinas to Pescadero;

California State Waters Map Series;

Colored, Shaded-Relief Bathymetry Offshore of San Francisco Map Area, California;

California State Waters Map Series—Offshore of San Francisco, California

Data Integration and Visualization Offshore of San Francisco Map Area, California