Scuba Diving Sea Of Cortez (Gulf of California)

The Sea of Cortez is one of the most diverse seas on the planet, and is one of UNESCO World Heritage Sites.  Jacques Cousteau, named the Sea of Cortez the “World’s Aquarium”.




The Sea of Cortéz is the body of water that separates the Baja California Peninsula from the Mexican mainland. It ihas a coastline of approximately 2,500 mi. Rivers which flow into the Gulf of California include the Colorado, Fuerte, Mayo, Sinaloa, Sonora, and the Yaqui. It is 700 miles long with a surface area is about 62,000 sq mi.

The Sea of Cortez is thought to be one of the most diverse seas on the planet, and is home to more than 5,000 species of micro-invertebrates.

It contains a large number of islands – the two largest being Isla Ángel de la Guarda and Tiburón Island, both located toward the northern end. Many of the islands are the result of volcanic explosions that occurred during the early history of Baja California and several islands, including Isla Coronado, are home to volcanoes.

Depths in the Sea of Cortez have ranged from a few feet at the estuary near Yuma, Arizona, to in excess of 9,800 ft in the deepest parts.

Significant portions of the Sea of Cortez have been designated as a “World Heritage Site” by the United Nations. This is because, “The Sea of Cortez and its islands are a natural laboratory for the investigation of speciation. Moreover, almost all major oceanographic processes occurring in the planet’s oceans are present in the property, giving it extraordinary importance for study.” The UN further describes it as an area of “striking natural beauty in a dramatic setting formed by rugged islands with high cliffs and sandy beaches, which contrast with the brilliant reflection from the desert and the surrounding turquoise waters.”

The World Wildlife Fund says that it “supports an extraordinary diversity of marine life, including many species of reef fish, sharks, whales, marine turtles, and the vaquita, the world’s smallest porpoise. The Gulf of California is Mexico’s most important fisheries region with commercial species of shrimp, sardine and giant squid. It is also important for sport fishing of billfishes and tuna.”


Heart-stopping underwater encounters await you on sites surrounding the many uninhabited wind-raked islands dotting the coastline of the Sea of Cortez. The plankton-rich currents of the Pacific along the western coast of California Sur plus the sheltered waters support whale sharks, dolphins, giant manta rays and schools of sharks such as scalloped hammerheads.

The narrow sea is home to a unique and rich ecosystem. In addition to a wide range of endemic creatures, it hosts many migratory species, such as the Humpback Whale, California Gray Whale, Killer Whale, Manta Ray and Leatherback Sea Turtle, and the world’s largest animal, the Blue Whale. There are unusual resident populations of Fin Whales and Sperm Whales that do not migrate annually. This region has historically been a magnet for world class sport fishing activities, with a rich history of sporting world records.

The Sea of Cortez sustains a large number of marine mammals, many of which are rare, and endangered. Its more than 900 islands are important nesting sites for thousands of seabirds and its waters are a primary breeding, feeding, and nursing ground for a myriad of migratory and resident fish species.

Both land based resorts and liveaboards give divers the opportunity to experience a vast array of diving possibilities, unmatched nearly anywhere else in the underwater world.


caboa san lucas

Cabo San LucasDivers will enjoy whole schools of tropical fish including puffers, angelfish, grunt and snapper. In addition, there are many rays and turtles and pristine beach coves to explore. A trip five out to Gorda Banks will let you explore a seamount that tops out at 130 feet. Moray eels hide in fronds of black coral while hammerheads, mantas and occasionally whale sharks cruise the currents.


Cabo PulmoNot enough can be said about the Mexican National Marine Park at Cabo Pulmo! It’s a diving experience not to be missed. Cabo Pulmo is the only living coral reef on the western coast of North America.

sea of cortez

La Paz: The hub of Baja eco-tourism, affords some of the best diving in the Sea of Cortez. There is a diversity of options: a shipwreck dive, a chance to swim alongside sea lions and the likelihood of shark encounters at the seamounts.

Mobula Ray at Isla Coronado

LoretoLoreto National Marine Park is home to over 800 species of fish, as well as invertebrates, Humboldt squid, sea lions, dolphins, sea turtles, whales, hammerhead sharks and whale sharks. There are also wonderful colored sea fans and black coral. The underwater cliffs of Los Candelleros, a triad of rocky mounts to the east of Danzante, drop precipitously to a rocky bottom at 200 feet.

puerto penasco

Puerto Panasco (Rocky Point): Located just 60 miles south of the US border in Arizona, Puerto Peñasco offers wonderful camping areas, great sites for open water training, coves, islands and a wealth of exotic marine life.


DIVING SEASON: Year-round. The best time is late June to early November. The absolute best months are September and October, when the seas are flat, visibility peaks at 60 feet or more.

In winter, surface water temperatures drop to 65 to 70F. Seas can kick up to two to three feet, and vis drops to an average of 30 to 50 feet due to plankton blooms. On the plus side, gray whales and occasionally blue whales move into the sea in winter to feed and mate, increasing your chances of an encounter.

VISIBILITY:  Summer time visibility peaks at 60 feet (18m) or more.  During the winter months the vis drops to an average of 30 to 50 feet (9-15m) due to plankton blooms.

WATER TEMPERATURE:  During the summer, surface temperatures hit a toasty 85F. It’s still cold enough below the thermocline that most divers opt for full 3mm wetsuits. In winter, surface water temperatures drop to 65 to 70F, so you’ll need a 5mm or 6mm full wetsuit with hood and gloves.

WEATHER:  Temperatures can soar to 110F in summer, but the average is more like 95F. In the winter, expect daytime highs in the low 70Fs. The sky is usually cloudless and the sun intense, so don’t forget the sunscreen.

SKILLS LEVELS: Dives for all diver skill levels are readily available.

WHAT TO EXPECTO SEE: The Sea of Cortez has a reputation for whale sharks. During the summer and fall, divers flock to the Sea of Cortez for a chance to swim with the largest sharks in the world, which generally move south as the season gets later. Another shark also put La Paz on the map in the ’80s, when divers could see massive schools of hammerhead sharks off El Bajo and Las Animas, but unfortunately these schools have been replaced with occasional hammerhead sightings. During the winter months, mobula rays are common. Manta rays are also sighted on occasion. Another main attraction for diving La Paz are the sea lions, which frolic and play with divers, presenting amazing photo opportunities. Sea Lions are found in a number of places in the Sea of Cortez, but none beat the sea lion colony of Los Islotes.

Other Sea of Cortez marine life includes huge schools of jacks and baitballs, as well as tuna, wahoo and lots of other fish, dolphins, eels, jawfish, rays. Macro life can also be good, including nudibranchs, shells and various crabs and shrimp.


More information on Mexico

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