Whenever I talk about penguins at public schools the two most common questions that students ask me is how long can penguins hold their breath and how deep can they dive. Of course the answer varies a great deal between penguin species, but now researchers have pinpointed to a great degree of accuracy the answer to these questions when it comes to Emperor penguins. Publishing in the Journal of Experimental Biology late this year, Katsufumi Sato (of the International Coastal Research Center at the University of Tokyo) and four others examined these abilities by affixing dive recorders to emperor penguins captured at a diving hole in McMurdo Sound, Antarctica (affectionately called the Penguin Ranch), and at a breeding colony at Cape Washington. In both locations, the penguins’ mean dive duration ranged from 1.7 to 3.0 minutes. Most dives lasted no longer than 10 minutes, and most dives did not exceed 100 metres. However, nine of the 10 tracked penguins dived deeper than 400 metres, and four of those made it to 500 metres. But the big news was the bird at Cape Washington known as CW8: It stayed under water for an incredible 27.6 minutes, setting a world record for underwater diving birds. Weighing 27.5 kilograms and employing a stroke-and-glide method of locomotion, CW8 reached a depth of 110 metres and then swam at depths ranging from 30 to 60 metres, reaching speeds of about two metres per second. Immediately after this amazing feat, the bird lay on its belly on the sea ice for about six minutes and then stood still on its feet for another 20 minutes before beginning to waddle about. Its next dive did not take place until eight hours later, either because it had filled itself with food on such a long dive or, more likely, because it was exhausted.