Cuvier's beaked whales are a rare sight—perhaps because they appear to be the deepest-diving mammals in existence. In a new study, researchers found that the creatures were able to reach a depth of nearly 1.9 miles, Reuters reports. In another record-breaking dive, a beaked whale was able to hold its breath for two hours and 17 minutes. Those figures surpass the 1.5-mile and two-hour dives of elephant seals, which, the BBC notes, had previously held those records among mammals.
The results come from 3,700 hours of diving data on eight tagged whales. The creatures' average dives measured almost 0.9 miles, and they usually lasted more than an hour, the Guardian notes. How do they do it? For one thing, their bodies have very reduced air spaces, notes an expert: "It is the presence of air spaces within the body that would crush a human at a fraction of the depths these whales can dive." What's more, their muscles are packed with a protein called myoglobin, which lets them store vast amounts of oxygen. (In 2010, scientists spotted the world's rarest whale—another species of beaked whale—for the first time.)