Cortes Bank

Cortes Bank
Cortes Bank near San Diego
Coordinates	32°28′41″N 119°12′54″W / 32.478°N 119.215°W / 32.478; -119.215Coordinates: 32°28′41″N 119°12′54″W / 32.478°N 119.215°W / 32.478; -119.215

Cortes Bank is a shallow seamount (a barely submerged island) in the North Pacific Ocean. It is 96 miles southwest of San Pedro, Los Angeles, 111 miles (166 kilometers) west of Point Loma San Diego, United States, and 47 miles (82 kilometers) south-west of San Clemente Island in Los Angeles County. It is considered the outermost feature in California's Channel Islands chain. At various times during geologic history, the bank has been an island, depending on sea level rise and fall. The last time it was a substantial island was around 10,000 years ago during the last ice age. It is quite possible that this island was visited by the first human inhabitants of the Channel Islands, most notably San Clemente Island, whose seafaring residents would have been able to see "Cortes Island" from high elevations on clear days.

The shallower reaches of the bank comprise about 15–18 miles of sandstone and basalt and they rise from the ocean floor from 1000 fathoms, or just over a mile depth. The bank has been described as a series of mountaintops, but really it is more of the shape of a wave-scoured mesa with a few hard, basaltic high spots along its length. The shallowest peak, the Bishop Rock, rises to between 3 and 6 feet (1–2 m) from the surface, depending on the tides. On very low tides, the rock can be visible in the trough of passing waves. Other shoal spots besides the Bishop Rock also spawn giant waves. These shoals range in depth from 30 to 100 feet and are a hazard to shipping. Nine Fathom spot is about 4.5 miles (7 kilometers) northwest of Bishop Rock and also rises to about 54 feet (18 m) below the surface. Both are noted scuba diving locations featuring clear water, vast kelp forests and abundant sea life. The Bishop Rock also creates a renowned big-wave surfing spot recognized as being capable of producing some of the tallest surfable waves in the world.