Whale Shark Snorkeling, Bahía de Kino and San Carlos

During the late summer and early fall, whale sharks, the world's largest fish, gather to feed on plankton blooms in the Sea of Cortez near Bahía de Kino and San Carlos, drawing licensed snorkel operators out to find and swim alongside them under strict wildlife-viewing rules. Only snorkeling, not scuba diving, is permitted around the animals, and boats and swimmers must maintain a respectful distance and limit group sizes to avoid stressing the sharks. No prior snorkeling experience is required, though participants should be comfortable in open water and able to swim; children are generally welcome from around age 8 with an adult, though this varies by operator. Wetsuits, snorkeling gear, and life vests are typically included in the tour price; participants should bring reef-safe sunscreen, since standard sunscreen is prohibited on many marine-wildlife tours. Guides brief swimmers on approach etiquette before entering the water and position the boat to give the best vantage without crowding the animals. Because sightings depend on the shifting location of plankton blooms, some tours include a scouting period by boat before finding sharks, and operators cannot guarantee an encounter on every outing, though the August-October season offers the highest probability.