Delta (D)
maritime signalsmaritimesignal flagnavigation
The Delta flag is yellow with a horizontal blue stripe through the center. It signals that a vessel is maneuvering with difficulty and other ships should keep clear. This might indicate a mechanical problem, restricted steering, or a complex towing operation that limits the ship's ability to change course quickly.
Large container ships in narrow channels often fly the Delta flag because their immense size and draft make it nearly impossible to take evasive action, giving them effective right-of-way over smaller vessels.
Adopted: 1857
