46 CFR § 169.561
Firemain
April 15, 2021
(a) Each vessel required to be provided with a power-driven fire pump must also be provided with a fire main, hydrants, hoses and nozzles.
(b) Fire hydrants must be of sufficient number and located so that any part of the vessel may be reached with an effective stream of water from a single length of hose.
(c) All piping, valves, and fittings must be in accordance with good marine practice and suitable for the purpose intended.