Realizing that the Skipper would notice Petty Officer Johnson's slight weight problem, he quickly blows up a large balloon to make himself look skinnier.
Skald, although all the replies were good, yours put my wife and I in hysterics. Two points!
FYI, this photo was taken just before a test flight of a Trident II ICBM. The crewman is launching a weather balloon just prior to the flight. My wife took the photo on the deck of the tender ship that was monitoring the flight. IIRC, it was launched from the USS Nevada, SSBN 733.