46 CFR §108.423

1. (a)A fire main system must have enough fire hydrants so that each accessible space may be sprayed with at least two spray patterns of water.
2. (b)In a main machinery space, except a shaft alley with no assigned space for stowage of combustibles, each spray pattern of water must be from one length of fire hose and each must be from a separate outlet. In all other spaces at least one spray pattern of water must be from one length of fire hose.
3. (c)No outlet on a fire hydrant may point above the horizontal.
4. (d)Each fire hydrant must have at least one spanner and at least one fire hose rack or reel.