Single letter codes.

Note: all codes marked * when made by sound must comply with the requirements of ColRegs 15 and 28.

 
A  Alpha - I have a diver down; keep well clear at low speed.
*B  Bravo - I am taking in, or discharging or carrying dangerous goods.
C  Charlie - Yes (affirmative or "the significance of the previous group should be read in the affirmative").
*D  Delta - Keep clear of me, I am manoeuvring with difficulty.
*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 a fishing vessel operating in close proximity to the fishing grounds: "I am hauling nets."
*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.
K  Kilo - I wish to communicate with you.
L  Lima- You should stop your vessel instantly.
M  Mike- My vessel is stopped and making no way through the water.
N  November - No (negative or "the significance of the previous group should be read in the negative"). This signal may be given only visually or by sound. For voice or radio transmission the signal should be "no" in response to a preceding signal).
O  Oscar - Man overboard.
P  Papa - [in harbour] All persons should report aboard 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 - Single letter code R has no allocated meaning.
*S  Sierra - My engines are going astern.
*T  Tango - Keep clear of me; I am engaged in pair trawling.
U  Uniform - You are running into danger.
V  Victor - I require assistance.
W  Whisky - I require medical assistance.
X  X-ray - 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 a fishing vessel operating in close proximity to the fishing grounds: "I am shooting nets."
 
Refs: IMCO 1965