These Adelie penguins look as if they are rushing out to greet the Navy ship. One of only two species restricted to Antarctica (the other species is the Emperor), the Adelie penguins range from eighteen to twenty-four inches high. The penguin became one of the symbols of Operation Deep Freeze I. The men in the painting are laying the "deadmen." A "deadman" is a large, thick piece of timber placed into a hole dug into an ice shelf far inland. It is buried under layers of snow and then water is poured over it, freezing it firmly into the sea ice. A mooring line, or steel cable, is fastened around it, attaching it to the ship. This line holds tight but also may be released instantly should an ice alert or blizzard warning be sounded.