Echo (E)
maritime signalsmaritimesignal flagnavigation
The Echo flag is divided horizontally into blue on top and red on the bottom. It indicates that a vessel is altering course to starboard (right). In congested waterways, this visual signal supplements sound signals and helps nearby vessels anticipate the ship's movements.
The Echo flag is particularly important in rivers and canals where vessels must signal turns well in advance. Combined with India (altering to port), these two flags help coordinate traffic in some of the world's busiest waterways.
Adopted: 1857
