Delta Flag

Yellow with a wide horizontal blue band across the center (yellow-blue-yellow), Delta is letter D of the International Code of Signals. Hoisted singly it means “Keep clear of me; I am maneuvering with difficulty,” telling other vessels the ship’s handling is impaired and that they should give it room, a meaning close to the COLREGs concept of a vessel restricted in its ability to maneuver. Bridge teams use it during constrained operations such as towing or dredging.