Restricted in Ability to Manoeuvre

Vessel Restricted in Ability to Manoeuvre — defined in COLREG Rule 3(g) as a vessel which from the nature of her work is restricted in her ability to manoeuvre as required by the Rules and is therefore unable to keep out of the way of another vessel. Examples include vessels laying or recovering navigational marks, dredging or surveying, replenishment underway, launching aircraft, mineclearance, and towing operations that severely restrict manoeuvrability. RAM vessels show by day a ball-diamond-ball; by night red-white-red all-round lights vertically. RAM has priority below NUC under Rule 18.