Quintana Roo Isla Mujeres

Sleeping Shark Cave on Isla Mujeres

For a long time, it was thought that sharks did not sleep because they had to swim to get oxygen. That is, until this cave in the Mexican Caribbean was discovered.

10-11-2023, 1:03:31 PM Por:

Thirty minutes by boat from Isla Mujeres, and about 65.6 feet underwater, lies this cave where several shark species rest from their journeys: this is the sleeping shark cave. This cave is unique, shedding new light on our knowledge of these animals.

Imagine exploring the depths of the ocean and seeing these awe-inspiring creatures in deep sleep.

cueva de tiburones dormidos
Photo: SECTUR México

Where Sharks Sleep

Sharks had never been observed sleeping due to their rapid metabolism, until this cave of sleeping sharks was discovered. The discovery completely changed our view of these fantastic animals.

For a long time, it was thought that sharks didn’t sleep because they need to swim to move water through their gills and thereby get oxygen. The only species that had been observed asleep was the nurse shark, which has slow metabolism. Only 50 years ago, Carlos Castillo García, a Mexican fisher, discovered a cave where sharks enter into a state of deep relaxation. It is believed that sharks can sleep here because of the underwater currents that allow them to breathe while resting.

Carlos fished lobster the old-fashioned way, diving deep into the water while holding his breath. He was the first person to notice this strange behavior, when he saw sharks entering the cave but not coming out. He bravely ventured in, in pursuit of the mystery. He was shocked to see many sharks resting inside the cave. Carlos says there were many species of sharks, such as nurse sharks, blue sharks, tiger sharks, mako sharks, whitetip sharks, and leopard sharks. The most dangerous species of sharks, just lying there asleep.

He then told his friend, Ramón Bravo, the best Mexican underwater cameraman, about his discovery. Both spread word about the cave, putting Isla Mujeres in the spotlight.

Visit Sleeping Shark Cave!

Despite what Hollywood movies would have you believe, sharks don’t usually attack humans without provocation. People can actually swim serenely alongside these beautiful creatures. So, if you are a thrill-seeker and know how to scuba dive, here you can swim among the most astonishing species of sharks in peace and harmony. Following all of your guide’s directions of course!

To get here, take a ferry from Cancún to Isla Mujeres. Once on the island, a boat can take you out to the cave. You must be a certified diver, as you will have to dive dozens of feet deep.