In the modern Navy, falsifying reports, records and
the like is often referred to as "gundecking." The origin of the term
is somewhat obscure, but at the risk of gundecking, here are two plausible
explanations for its modern usage. The deck below the upper deck on British
sailing ships-of-war was called the gundeck although it carried no guns. This
false deck may have been constructed to deceive enemies as to the amount of
armament carried, thus the gundeck was a falsification.
A
more plausible explanation may stem from shortcuts taken by early Midshipmen
when doing their navigation lessons. Each Mid was supposed to take sun lines at
noon and star sights at night and then go below to the gundeck, work out their
calculations and show them to the navigator. Certain of these young men,
however, had a special formula for getting the correct answers. They would note
the noon or last position on the quarter-deck traverse board and determine the
approximate current position by dead reckoning plotting. Armed with this
information, they proceeded to the gundeck to "gundeck" their
navigation homework by simply working backwards from the dead reckoning
position.