Delta

Phonetic alphabet letter D or a type of anchor. A delta refers to a landform created at the mouth of a river where it flows into an ocean, sea, or lake.

When a vessel displays the Delta flag, it indicates that it is having difficulty manoeuvring and may not be able to follow standard navigational rules. This signal alerts other vessels in the vicinity to give the vessel displaying the Delta flag a wide berth to avoid collisions or other navigational hazards.

Flag

Code Flag Delta (D)

Nautical or signal flags are used at sea to convey messages over long distances. Only black, blue, red, white and yellow are used because these are the only colours readily distinguished at sea. Many different coding schemes have been used, but the International Code is the most common.