Q-Ship

A Q-ship is a decoy armed merchant vessel disguised as an unarmed trader to lure attackers, especially submarines, into close range before unmasking concealed guns and opening fire. The Royal Navy fielded Q-ships against German U-boats in both world wars, the name deriving from their Queenstown (Cork) base. The tactic is largely historical and its legality is debated under the law of naval warfare, since it exploits the protected status of merchant ships; it survives in doctrine as a reference point for deception and false-colors operations at sea.