The greatest depth accurately measured for any bird is 534 m (1,751 ft) by a 29-kg (63-lb 14.4-oz) emperor penguin (Aptenodytes forsteri) at Coulman Island, Ross Sea, Antarctica, and recorded by Professor Gerald Kooyman of the Scripps Institution of Oceanography in November 1993.

Kooyman measured almost 16,000 dives from five different birds, the longest of which lasted 15.8 minutes.