Signal Flags Meanings | Navy Signal Flags | All Star Flags

Signal Code Flags

For centuries, admirals have used flags as signals to communicate a single message to other members of a fleet. As tactics began to require more and more signals, a more complex code of signals was needed. In 1738, a French naval officer named Mahé de la Bourdonnais purportedly devised the first numerical flag code, assigning a different flag to each number, 0 through 9. With three sets of flags, a ship could make 1,000 different combinations of three-flag signals. Then, in 1790, the British Royal Navy introduced the use of substitute or repeater pennants so that only one set of flags was needed, and the first alphabetic flag signal system in 1800. Also during this period, the United States Navy was working to develop its own marine signaling system, focusing largely on numeric signal flags hoisted inverted or in specific combinations. It wasn’t until 1857 that the British Board of Trade developed a code that had not only the previous numeric flags but also flags for alphabetic letters as well, although only 18 of them. The number of signals that could be constructed jumped to more than 20,000 in three-flag combinations, and in 1870 this system was renamed the International Code of Signals. The ICS is currently maintained by the International Maritime Organization, which published a new print edition in 2005.

Today, Navy signal flags are used when communicating among allied forces, while the ICS is used with all other vessels. The code/answer pennant precedes all signals using the ICS. Navy signalmen transmit messages while maintaining radio silence by hoisting a flag or series of flags on a halyard. One-flag signals are urgent or very common signal flags meanings as seen below:

**Signal Code Flags**
Flag	Name	Navy Meaning	International Meaning
	Alfa	I have a diver down; keep well clear at slow speed.	---
	Bravo	I am taking in, discharging, or carrying dangerous cargo.	---
	Charlie	"Yes" or "affirmative".	---
	Delta	I am maneuvering with difficulty; keep clear.	---
	Echo	I am directing my course to starboard.	---
	Foxtrot	I am disabled; communicate with me. On aircraft carriers: Flight Operations underway	---
	Golf	I require a pilot.	---
	Hotel	I have a pilot on board.	---
	India	Coming alongside.	I am directing my course to port.
	Juliet	I am on fire and have dangerous cargo; keep clear.	---
	Kilo	I wish to communicate with you.	---
	Lima	You should stop your vessel immediately.	---
	Mike	My vessel is stopped; making no way.	---
	November	No or negative.	---
	Oscar	Man overboard.	---
	Papa	All personnel return to ship; proceeding to sea (Inport).	---
	Quebec	Boat recall; all boats return to ship.	Ship meets health regs; request clearance into port.
	Romeo	Preparing to replenish (At sea). Ready duty ship (Inport).	None.
	Sierra	Conducting flag hoist drill.	Moving astern.
	Tango	Do not pass ahead of me.	Keep clear; engaged in trawling.
	Uniform	You are running into danger.	---
	Victor	I require assistance.	---
	Whiskey	I require medical assistance.	---
	Xray	Stop carrying out your intentions and watch for my signals.	---
	Yankee	Ship has visual communications duty.	I am dragging anchor.
	Zulu	I require a tug.	---
	Code/Answer	Flag that follows is from the International Code of Signals.	Message is understood. Also, numeric decimal point.
	First Substitute	Absence of flag officer or unit commander (Inport).	Substitute for the first flag in this hoist.
	Second Substitute	Absence of chief of staff (Inport).	Substitute for the second flag in this hoist.
	Third Substitute	Absence of commanding officer (Inport).	Substitute for the third flag in this hoist.
	Fourth Substitute	Absence of civil or military official whose flag is flying on this ship.	Substitute for the fourth flag in this hoist.
	One	Numeral one.	None.
	Two	Numeral two.	None.
	Three	Numeral three.	None.
	Four	Numeral four.	None.
	Five	Numeral five.	None.
	Six	Numeral six.	None.
	Seven	Numeral seven.	None.
	Eight	Numeral eight.	None.
	Nine	Numeral nine.	None.
	Zero	Numeral zero.	None.
	Pennant One	Pennant one.	Numeral one.
	Pennant Two	Pennant two.	Numeral two.
	Pennant Three	Pennant three.	Numeral three.
	Pennant Four	Pennant four.	Numeral four.
	Pennant Five	Pennant five.	Numeral five.
	Pennant Six	Pennant six.	Numeral six.
	Pennant Seven	Pennant seven.	Numeral seven.
	Pennant Eight	Pennant eight.	Numeral eight.
	Pennant Nine	Pennant nine.	Numeral nine.
	Pennant Zero	Pennant zero.	Numeral zero.