1. A Beaked Whale Stayed Under for 222 Minutes, Far Beyond What Its Oxygen Should Allow
The Cuvier's beaked whale, sometimes called the goose-beaked whale, is a medium-sized whale about 15 to 23 feet (roughly 4.5 to 7 meters) long. It lives in most oceans and likes deep water over the edge of the continental shelf. It hunts mostly squid, and sometimes fish and crustaceans[1]. It is hard to watch from a boat, because it spends so little time at the surface. Tags are how scientists learned what it does below.
The numbers are startling. NOAA Fisheries lists the deepest known dive as 9,816 feet (2,992 meters, nearly two miles) and the longest as 222 minutes, or 3 hours 42 minutes[1][2]. The 222 minutes beat the earlier record of 137.5 minutes, which was set by a whale tagged off California[2][4]. The same California study recorded the 2,992-meter dive[4].
Records are the extremes, so it helps to ask what an ordinary dive looks like. In a study of 3,680 dives by 23 whales, the median length of a feeding dive was 59 minutes, and 5 percent of dives lasted more than 77.7 minutes[3]. In the California study, the deep dives averaged 1,401 meters (about 4,600 feet) and 67.4 minutes, with roughly 100 minutes of rest between deep dives on average[4]. Even the ordinary dive is more than twice what the oxygen sum predicted[2].
So where does all that oxygen come from? The first place to look is the place most people would guess.
2. Deep Divers Keep Their Oxygen in Blood and Muscle, Not in the Lungs
When you take a big breath before a swim, you are loading the lungs. It feels like the obvious store of oxygen. But a physiology review by Gerald Kooyman and Paul Ponganis reports that in animals that dive deep, more than 80 percent of the oxygen store sits in the blood and the muscles[5]. Their table puts the range at 80 to 90 percent[5].
That comes from more blood, more red cells, and more hemoglobin than a land animal of the same size would have. The review also names a hallmark of animals that dive deep: a much higher concentration of myoglobin in the muscles[5]. Myoglobin is a protein that picks up oxygen and holds it inside muscle cells. A simple way to picture it is a backpack, though there is no bag: the oxygen is held on the protein itself.
A pack that full raises a new problem, though. Proteins packed this tightly can be expected to clump together.
3. A Slight Electric Charge Keeps Packed Myoglobin from Clumping
In 2013, a team led by Scott Mirceta and Michael Berenbrink compared myoglobin across living mammals. They found that the diving species, from 16-gram water shrews to 80,000-kilogram whales, share a signature: a high net electric charge on the surface of the myoglobin molecule. That charge goes along with much higher myoglobin concentrations in the muscle[6].
Why does charge matter? Molecules with the same kind of charge push each other away, like two magnets pushed together with matching ends. As one science writer put it, the extra charge lets deep divers pack myoglobin at higher concentrations without it clumping together uselessly[7]. The magnet image is only a picture: the real force is electrical, not magnetic.
The pattern is strong enough to predict with. Combining the surface charge with body mass predicts 82 percent of the variation in maximum dive time across living mammals[6]. It predicts the maximum dive time of a species, not the length of one particular dive.
4. Slow Heartbeats and Narrowed Blood Vessels Make the Stored Oxygen Last
A big account is only half the story. The other half is how slowly it is spent. In animals that dive, the heart rate drops during a dive (bradycardia) and blood vessels in less urgent tissues narrow. On the occasional very long dive, this keeps the oxygen in the blood for the brain and heart[5].
The slowdown is not the same in every dive. The review notes that the heart-rate drop during dives to depth varies, and probably depends on the nature of the dive[5]. For beaked whales, the researchers behind the 222-minute record suggest a combination: a low metabolic rate, large oxygen stores, and a high ability to handle the acid that builds up when muscles run without oxygen[3]. They describe this as a suggestion, not a measurement.
5. Under Pressure the Lungs Collapse, Which Helps Protect the Whale from the Bends
Down in the deep, water pressure squeezes the body. Divers who breathe air from a tank know a danger here: nitrogen dissolves into the blood under pressure, and if a diver rises too fast it can form bubbles, causing decompression sickness, or "the bends." In diving mammals, the review says, the lungs collapse at fairly shallow depths, which limits how much nitrogen gets absorbed. Blood nitrogen stays below the level that causes decompression sickness[5].
How deep is "shallow"? It depends on the animal and on how it was measured. A study of one adult female California sea lion, over 48 dives, put lung collapse at about 225 meters (give or take 25 meters). Deeper dives collapsed the lungs deeper, and about 75 percent of the variation in collapse depth was explained by the depth of the dive[8]. For Weddell and elephant seals, nitrogen measurements put collapse at roughly 20 to 50 meters, and for bottlenose dolphins about 70 meters[5].
None of these numbers comes from a beaked whale. The same review points out that it is still debated whether large whales dive with full or partial lungs[5]. What a Cuvier's beaked whale's lungs do at 2,992 meters has not been measured in the sources used here.
6. Why Do the Longest Dives Still Surprise the Scientists?
Back to the opening question. A large oxygen store in blood and muscle, a slow rate of spending, and lungs that collapse rather than fill the blood with nitrogen all help explain why these whales can stay under for an hour. They do not yet explain 222 minutes. The researchers who calculated the 30-minute limit suggest the whales may also tolerate lactic acid building up in their muscles[2].
One more surprise: the team expected whales to spend longer at the surface recovering after very long dives, but found no clear pattern[2][3]. In other words, the whales rest less than the oxygen sum would suggest. That is a gap in knowledge, and it is a good place for a curious reader to keep looking.
How to Explore a Whale's Dive Yourself
- Measure two miles on a map. Use a map or a map app to find a place about 3 kilometers (nearly two miles) from your home, and think about how long it would take to walk there. The whale went that far straight down, in the dark, with no air.
- Compare with a movie. Look up the running time of a long film. A typical feeding dive of 59 minutes is about one television episode. Is the 222-minute record longer than the film you picked?
- Draw the oxygen account. On a piece of paper, sketch a whale and mark the three places in sections 2 to 5: blood, muscle, and lungs. Which one gets the biggest share? Then check your drawing against the Kooyman and Ponganis review listed below.