HMS Royal James (1671) in the context of "Fire ship"

A fire ship or fireship is a large wooden vessel set on fire to be used against enemy ships during a ramming attack or similar maneuver. Fireships were used to great effect against wooden ships throughout naval military history up until the advent of metal-hulled ships; they could also serve a considerable function in shock and awe strategies to harm the morale of enemy crews. Ships used for fireship tactics were typically purpose-built or retrofitted from surplus or obsolete vessels, either of which could be filled with gunpowder or other combustibles before a battle, but could also be improvised from warships in active combat purposely set on fire during engagements, such as if a vessel expended its munitions or had some other reason to be abandoned in battle.

Specialized fire ships included the massive Dutch hellburners, also called "explosion ships", which were fitted with large explosive stores designed to detonate upon contact with the enemy. Fireships were used to great effect by the outgunned English fleet against the Spanish Armada during the Battle of Gravelines, the Dutch in the raid on the Medway, Chinese warlord Sun Quan in the Battle of Red Cliffs, and the Greeks in their war of independence.