DECOY, in naval affairs, a stratagem employed by a ship of war to betray a vessel of inferior force into an uncautious pursuit, until she has drawn her within the range of her cannon, or what is called within gun-shot distance. It is usually performed by painting the stern and sides in such a manner as to disguise the ship, and represent her either as much smaller and of inferior force, or as a friend to the hostile vessel, which she endeavours to ensnare, by assuming the emblems and ornaments of the nation to which the stranger is supposed to belong. When she has thus provoked the adversary to chase, in hopes of acquiring a prize, she continues the decoy, by spreading a great sail, as endeavouring to escape; at the same time that her course is considerably retarded by an artful alteration of her trim, till the enemy approaches. Decoying is also performed in order to elude the chase of a ship of a superior force in a dark night, by throwing out into the sea a lighted cask of pitch, which will burn for a considerable time, and thus mislead the enemy. Immediately after the cask is thrown out, the ship changes her course, and may easily escape, if at any tolerable distance from the foe.