 The term "monitor" may be derived from the class of warships known by the same name, that were armed with disproportionately large guns.Deluge guns are often fitted to fire boats, tug boats, and on top of large fire trucks for use in manual firefighting efforts, where they can be aimed and operated by one firefighter and are used to deliver water or foam from outside the immediate area of the fire.Deluge guns are sometimes installed in fixed fire protection systems to protect high hazards, such as aviation hangars and helicopter landing pads.