Swim with the majestic whale sharks of the Sea of Cortez

Whale sharks – the largest fish in the ocean and return every winter to the waters of the Bay of La Paz. Swimming with these gentle giants can be the perfect end to a dive trip or island outing.

From early winter until late spring the whale sharks can be found feeding in the rich waters of the Sea of Cortez and in the Bay of La Paz in Baja California Sur. The gentle giants of the sea are the largest fish in the world and each season return to the waters close to the city of La Paz.

Seeing these ocean behemoths in their natural environment or swimming close to these fish can be an exciting outing for young and old. Island tour boats that visit the Isla Espiritu Santos or the sea lion colony at Los Islotes often close the trip with a whale shark encounter. 

Whale sharks are fish, not air-breathing mammals, as they come from the family of the second part of their name, sharks, and the Rhincodon genus. These giant filter-feeding fish are known scientifically as Rhincodon typus eat amongst the smallest creatures in the ocean , plankton. Moving slowly through the water, filtering thousands of gallons per day, these fish glean their nutrients from the rich winter waters of the Sea of Cortez.

Whale sharks are the largest known species of fish, growing to 12.5 meters and can weigh as much as 79,000 pounds. The whale sharks here in La Paz are often 7-10 meters in length. The fish can live as much as 70 years. The species originated about 60 million years ago. Whale sharks have very large mouths, they feed mainly, though not exclusively, on plankton, microscopic plants and animals, and occasionally on small fish.

Once plentiful in the waters of the worlds oceans, the whale sharks are an endangered species and protected under international and Mexican law. They are not good eating. 

A variety of tour operators in La Paz can take you to see the whale sharks. As of 2015 private vessels are prohibited from visitng the whale shark areas, providers authorized to tour the whale sharks are required to fly an identification banner on the vessels visiting the area.  Since the waters of the Sea are relatively cold in the winter time, dropping into the upper 60’s, a 3-7mm wetsuit makes the experience much more inviting if you plan on getting in the water.

Free diving only is permitted near the whale sharks, scuba tanks are not allowed. The whale sharks are usually found near the middle of the spit of land that extend out in front of La Paz, known as the Magote. There is a drop off where the 2-3’ meter depths that extend out from land and drop quickly to 7-10 meters. Currents in the area often form a rich up welling that provides food for the whale sharks. In the afternoons the location can often be determined by the cluster of tour vessels. 

Once sighting the whale sharks maintain speeds of less than 3kts, and approach the fish. They usually are found in schools of 3-5 fish. Since they do not surface for air they can be more difficult to locate. 

Look for areas of unusual wave breaks or ‘footprint’ in calm water. Take care when piloting your vessel, with the small population of whale sharks in the Bay you do not wish to become infamous for being the skipper to strike a whale shark. Motorized vessels should maintain a distance of 20 meters. Do not harass the fish or toss food at them, they wouldn’t be interested in anything you eat. 

If you wish to get in the water with whale sharks it can be an unforgettable experience. First, remember you present far more danger to the fish than the fish does to you. Stay clear of the whale shark, give the marine giant at least 2 meters of space. Do not touch the fish, the touch of the whale sharks skin can leave them open to life-threatening infection. With the fish moving so slowly and docilely, it is difficult to resist the urge to make contact. Giving the fish distance also provides you some safety, as it is still a large animal moving freely in the wild. A brisk movement of the tail to escape intruders can cause injury to swimmers. It is a breath taking experience to look eye to eye with a creature this large.

Take plenty of pictures and video, you will certainly want to remember your encounter with the whale sharks of La Paz and take the proof back to your unbelieving friends back home. Do your part to protect these endangered species in the Sea of Cortez.