When you start diving into the world of marine mammals, incredible records begin to emerge. Daily, these creatures of land and sea are torn between two of their most basic needs: oxygen and food.

Nevertheless, they fearlessly plumb the depths of the ocean and withstand tremendous amounts of water pressure in search of their favorite treats and eats — even when it takes them thousands of feet away from the ocean’s surface and air. But which marine mammal holds the record for the world’s deepest dive? Keep reading for the full scoop.

Fur Seals

Although they generally prefer sticking to shallower waters, fur seals are capable of descending up to 984 feet under water. Commonly found in the waters off southern Australia, these cousins of sea lions are sometimes spotted mid-descent by deep tow cameras. What motivates fur seals to occasionally venture hundreds of feet below the surface? The hunt for bony fish, octopus, and squid.

fur seal pup resting on a rock

Sperm Whales

That’s still nothing compared to sperm whales, which can hang out 7,382 feet below the waves. Like fur seals, sperm whales can’t resist the chance to nosh on a meal of cephalopods. But unlike their furry counterparts, sperm whales prefer giant squid, a deep-sea delicacy haunting the ocean’s twilight zone. Astonishingly, sperm whales still aren’t the deepest divers.

Sperm whale

Southern Elephant Seals

Southern elephant seals can hit 7,835 feet beneath the waves! What helps these extreme marine athletes go so deep and stay there for so long? Elephant seal blood contains more red blood cells than other marine mammals, and they tolerate carbon monoxide levels ten times higher! However, these staggering numbers still don’t take the cake.

Cuvier’s Beaked Whale: The Deep-Sea Diving G.O.A.T.

The sea creatures listed above can do some downright incredible things. But they don’t hold a candle to the veritable G.O.A.T. (Greatest of All Time) of bottomless divers: Cuvier’s beaked whale. What does the planet’s deep-diving champ look like? It’s shaped kind of like a sausage and measures up to 22 feet long.

Two Cuvier's beaked whales swimming at the water's surface.

Cuvier’s beaked whales. Image credit: Laurent Bouveret via Wikimedia Commons (CC BY-SA 4.0).

While Cuvier’s beaked whales prove smaller than most baleen whales, they still outsize other beaked whales. Found throughout the world’s oceans, they boast a population of more than 100,000. But we’re here to focus on their impressive dives, which rank the deepest among marine mammals — 9,816 feet, to be exact. As you might have imagined, they also outrank other marine mammals in terms of time beneath the water. One individual spent 3 hours 42 minutes underwater without coming up for a breath!

Scientists still have a long way to go when it comes to understanding why they dive so deep and how often they do it. But they have discovered that Cuvier’s beaked whales are excellent at flattening their lungs while diving, decreasing the amount of air space they have to keep inflated under the intense pressure of so much water. They also spend a lot of time gliding, rather than swimming, through the water to conserve their energy.

Honorable Mentions

What are some other competitors for the world’s deepest divers? They include animals that don’t fit the mammal mold but still deserve honorable mentions.

Whale sharks are the largest fish in the world and can dive down 5,905 feet, considerably upping the ante for the mammal diving record.

Representing deep-diving birds are emperor penguins, which can dive 1,640 feet below the surface on the hunt for food in the frigid waters off the Southern Ocean.

But these flightless birds have nothing on leatherback turtles, marine reptiles which can swim to depths of 3,937 feet!

Take a Deep Dive into Adventure

Want to learn more about marine life? Maybe even get up close and personal with some of the ocean’s most fascinating inhabitants? We’ve got you covered! Find a Ripley’s Aquarium near you, and let the splashy fun begin!

By Engrid Barnett, contributor for Ripleys.com


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