IMO Flag

A

Alfa
I have a diver down; keep well clear at slow speed.

With three numerals, azimuth or bearing.

B

Bravo
I am taking in, or discharging, or carrying dangerous goods. (Originally used by the Royal Navy specifically for military explosives.)

C

Charlie
Affirmative.

With three numerals, course.

D

Delta
Keep clear of me; I am maneuvering with difficulty.

With two, four, or six numerals, date.

E

Echo

I am altering my course to starboard.

F

Foxtrot

I am disabled; communicate with me.

G

Golf

I require a pilot. When made by fishing vessels operating in close proximity on the fishing grounds it means: "I am hauling nets".

With four or five numerals, longitude. (The last two numerals denote minutes and the rest degrees.)

H

Hotel

I have a pilot on board.

I 

India

I am altering my course to port.

J

Juliet

I am on fire and have dangerous cargo on board: keep well clear of me, or I am leaking dangerous cargo.

K

Kilo

I wish to communicate with you.

With one numeral, I wish to communicate with you by; 1) Morse signalling by hand-flags or arms; 2) Loud hailer (megaphone); 3) Morse signalling lamp; 4) Sound signals.

L

Lima

In harbor: The ship is under Quarantine. At sea: You should stop your vessel instantly.

With four numerals, latitude. (The first two denote degrees and the rest minutes.)

M

Mike

My vessel is stopped and making no way through the water.

N

November

Negative.

O

Oscar

Man overboard (often attached to the man overboard pole on boats).

P

Papa

The Blue Peter. In harbor: All persons should report on board as the vessel is about to proceed to sea. At sea: It may be used by fishing vessels to mean: "My nets have come fast upon an obstruction".

Q

Quebec

My vessel is "healthy" and I request free pratique.

R

Romeo

The way is off my ship.

With one or more numerals, distance in nautical miles.

S

Sierra

I am operating astern propulsion. With one or more numerals, speed in knots.

T

Tango

Keep clear of me; I am engaged in pair trawling.

With four numerals, local time. (The first two denote hours and the rest minutes.)

U

Uniform

You are running into danger.

V

Victor

I require assistance.

With one or more numerals, speed in kilometers per hour.

W

Whiskey

I require medical assistance.

X

Xray

Stop carrying out your intentions and watch for my signals.

Y

Yankee

I am dragging my anchor.

Z

Zulu

I require a tug. When made by fishing vessels operating in close proximity on the fishing grounds it means: "I am shooting nets".

With one or more numerals, time (UTC). (The first two denote hours and the rest minutes.) (Origin of the phrase 'Zulu Time'.)