Gun Deck

The term gun deck originally referred to a deck aboard a ship that was primarily used for the mounting of cannon to be fired in broadsides. However, on many smaller vessels such as frigates and unrated vessels the upper deck, forecastle and quarterdeck bore all of the cannons but were not referred to as the gun deck. The completely covered level under the upper deck was, however, still called the gun deck although it had no guns at all.

On board marine seismic survey vessels, the lowest deck on the ship is normally referred to as the gun deck. This deck carries the seismic source arrays, consisting of air guns arranged in clusters.