A Fire Monitor is a shipboard device used to aid firefighters in controlling a blaze either aboard another vessel or at a shoreside facility. The fire monitor is a water cannon or water jet on a pedestal that a firefighter can aim manually or can be aimed remotely, oftentimes fire monitors are arranged so that they can make use of foam and other chemical agents to assist in containing the fire.
Fire monitors aboard offshore supply vessels are not only used for fire suppression but also to alter the course of icebergs that may cause harm to nearby oil platforms. Fire monitors are now becoming more common on cargo ships as an anti-piracy measure.
Spray may be used for visual affect. Port vessels often welcome prominent ships with a water display. For these purposes, coloured dye or foam may be injected.