Until 1978, no diver had explored the Cordell Bank. This extraordinary place is now a National Marine Sanctuary. There’s an interesting history behind how this part peperocc of the ocean off the coast of California, northwest of San Francisco became a sanctuary.
The bank was discovered by George Davidson while conducting surveys along California’s north coast in 1853. Sixteen years later, in 1869, a more extensive voteherd survey was conducted by Edward Cordell, after whom the bank was named. What follows is some of the experiences shared by the first divers to view the bank.
At 150 feet, air bubbles slide out of my regulator sounding like gravel being poured from a metal bucket. We are 20 miles from the nearest shore on a ridgetop of a large Pacific seamount named the Cordell Bank and the scene below is incredibly bright. Anemone, hydrocoral, sponges, and algae cover everything in sight, in many places growing on top of each other.
While collecting some of these organisms, origaniz we are suddenly flushed with a euphoric giddiness. We try to smile, but numb lips and the regulator make the effort that much sillier. Struggling to control the narcosis, we keep collecting and exploring. All too soon, however, my buddy waves a thumbs-up in front of my mask. Now, where’s the ascent line? A flashing strobe catches my eye and I swim toward it. The line’s there, so we follow our bubbles – but not to the surface. At 10 feet, we both grab the regulators of full scuba tanks. The decompression wait seems eternal as we can hardly wait to tell the others about our dive to where no one has been before.
These experiences were shared with the author from Robert Schmeider, Ph.D., of Walnut Creek, California, who was obsessed with the exploration of Cordell Bank. In 1977, while studying a chart of northern California’s coastline, this atomic physicist became intrigued by Cordell Bank, afrihand which is 20 miles (32 km) due west of Point Reyes and to the northwest of San Francisco. The chart showed there was at least one shallow place with a depth of 20 fathoms or 120 feet (37 meters). It could be dived using regular scuba tanks, so Schmeider assumed it had been. But when he asked a few diving friends if they had ever been there, he discovered none had. So he talked to people with the Coast Guard, the Navy, the California Academy of Sciences, the University of California at Berkeley, the Department Fish and Game, the Geological Survey, the National Oceanic and Atmospheric Administration (NOAA) and others. After a couple of months, Bob realized to his amazement, no one knew much about the bank at all. The idea of exploring Cordell Bank soon became a serious goal.
But Bob expected many dangers. Deep-diving can always be dangerous, especially with compressed air scuba diving due to the possibility of nitrogen narcosis and decompression problems. Additionally, he knew the water was cold, and a fairly stiff current of one or two, highdean knots ran in the area. Two knots is nearly impossible to do any work in. To make matters even worse he expected to encounter lots of sharks, including great whites since Cordell Bank lies about midway between Tomales Bay and the Farallon Islands, both places where great whites are known to congregate.
The fisherman in Bodega Bay knew the Bank well as an excellent fishing area, so Bob lined up a boat and skipper from there. After extensive discussions with several of his regular diving partners, he announced his plan to divers in the Sierra Club’s Loma Prieta chapter from the San Francisco Bay area in October of 1977. He knew exploring the bank would require a large support group. At an organizational meeting held in the U.S. Geological Survey chambers in Menlo Park, the group elected a divemaster and all but one of the 40 people attending pitched in $40 a piece to kick off Cordell Bank Expeditions.
After a few practice dives at Monterey and at the Farallon Islands, Bob felt his group was ready to go to Cordell Bank. Unfortunately, he ran into numerous difficulties. Most importantly, a number of divers had dropped out of the group, so Bob had trouble gathering enough divers for a trip. Finally, on October 20, 1978, with just five divers, Bob made it to Cordell Bank.
As Bob recalls, “What we saw on that day absolutely astonished us. We were totally unprepared for the light level. Not only was it not dark, it was incredibly light. After I made the first dive with a buddy, I told the other drivers not to take their lights, as they simply would not need them. It was so light you could almost read. And we had been to a depth of close to 150 feet.”
“There were enormous aggregates of 12-inch (30 cm) fish swimming around above the pinnacle. To us, it seemed an incredible snowstorm of fish. When we finally broke through the fish on our way down, our entire field of vision was just filled with this miraculous sight. We could see colors – reds and oranges and yellows – and the rocks were covered, just inundated, with organisms. Sponges, especially Corynactics (Strawberry anemone), pink hydrocoral, hydroids, and a lot of large-bladed algae. It looked as if someone had landscaped it. We were just overwhelmed.”
On the first dive, they collected nearly 50 species, including at least one new genus of algae and one new species. By working closely with a number of professional biologists at the University of California at Berkeley, the California Academy of Sciences, the Los Angeles County Museum, the Geological Survey, the Smithsonian, and other institutions, they sorted and identified their new collections until the list included more than 400 species.
After that first dive, made possible by the Sierra Club divers and by grants from such organizations as the San Francisco Foundation and the National Geographic Society, the Cordell Bank Expeditions evolved into a member-supported, systematic, data-gathering organization that bought its own research vessel, the Cordell Explorer, which was retired in 2014. They bought a LORAN-C receiver and carried out depth surveys back and forth across certain areas, measuring depths and recording positions. From that data, they were able to generate their own set of charts. Those charts became a major help in carrying out more successful dives, as they could more reliably find the pinnacles and ridges they wanted to dive. In the summer of 1985, Bob and a colleague were able to obtain state-of-the-art hydrographic survey data on the Bank as a result of a project conducted by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS). That survey covered the 200-mile Exclusive Economic Zone (EEZ) off the coast that the U.S. claims control over. Cordell Bank may well be the best-surveyed feature off the coast of North America.
Aside from collecting specimens and surveying, the expedition also used 35-millimeter photography, plus Super 8-millimeter, 16-millimeter, and videotape cinematography. Some of their photographs have been useful in identifying species that didn’t show up in their collections and in showing physical features the divers may not have noticed during their dives.
They have found this seamount is roughly elliptical and, at the 50-fathom depth, it is 9-1/2 miles long by 4-½ miles wide (15.3 x 7.25 km). It lies right on the edge of the continental shelf and is the northernmost such shallow place all the way to Canada. The bank is a distinct plateau with its flat top rising to the 30- to 35-fathom depth. Atop this plateau, at least four cliffy ridge systems, two in the north and two in the south, and several pinnacles reach to diveable depths. In fact, the shallowest point the expedition has found is about 19 fathoms (114 feet or 35 meters) and is part of a ridge system in the northeast. Geologically, it is considered a piece of the ancient Sierra Nevada that was sheared off by the Pacific Plate, thus explaining its granite composition.