This type of boats are specially designed for fighting fires on ships and aircraft on sea as well as building on the shore, which could include such multiple and complicated tasks as water rescue, pumping water out from flooded ships, disposition of spilled oil, and distribution of large amount of water to onshore pumpers. They are owned and operated mainly by local governments and the Japan Coast Guard.

To carry out their duties, they are provided with a fire pump, water monitor with sliding towers, dry chemical powder system for oil fires, as well as oil dispersion system.

Water monitor discharge sea water pumped and supplied by a pump driven by its dedicated engine or main engine for propulsion. Fire-extinguishing agent can be mixed with the water for fighting special fires on tankers.
Other than water monitor, they are equipped with water distribution ports to supply water to onshore fire engines and protection spraying apparatus to guard themselves from fires.

Although they are relatively small in size (approximately 200t), with a very powerful engine (over 3000hp) onboard and a propeller that can horizontally swivel round, they are capable of pulling and towing large vessels in narrow areas in a port, guiding and supporting them to safely reach and leave the shore.
Many of them working in ports in Japan are equipped with the water monitor so that they can promptly tackle unexpected shipboard fires.
they are carrying out a lot of tasks and duties to ensure maritime safety, in particular safety in ports, including escorting vessels, watching over loading and unloading, fighting fires, and cleaning spilled oil.