In 2020 scientists tracking a beaked whale logged a dive that seemed physically impossible: 3 hours and 42 minutes underwater on a single lungful of air, by far the longest dive ever recorded in any mammal on Earth

Take a Cuvier’s beaked whale, work out its body size and how much oxygen it can plausibly carry, and an earlier calculated aerobic dive limit gives you about 33 minutes. They wanted to estimate the whales’ behavioural aerobic dive limit and test whether exceptionally long dives were followed by longer recovery periods. Across the dives as a whole, longer dives were generally followed by longer intervals before the next deep dive. As Quick put it, “Going into the study, we thought that we would see a pattern of increased recovery time after a long dive. The earlier calculated aerobic limit was 33 minutes.