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Nautical Flags
Type a name or a word and see it spelled in nautical flags, with the phonetic name under each flag. Below is the whole nautical flag alphabet and what each flag means when a ship flies it alone.
What do these flags say at sea?
Nautical flag alphabet
These are the 26 letter flags of the International Code of Signals, the maritime signal flags used by ships of every country. Each flag stands for a letter, has a phonetic name (Alfa, Bravo, Charlie…) and, flown alone, carries its own message.
What each maritime signal flag means
| Flag | Name | Meaning when flown alone |
|---|---|---|
| A | Alfa | I have a diver down; keep well clear at slow speed. |
| B | Bravo | I am taking in or discharging or carrying dangerous goods. |
| C | Charlie | Affirmative. |
| D | Delta | Keep clear of me; I am maneuvering 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. |
| H | Hotel | I have a pilot on board. |
| I | India | I am altering my course to port. |
| J | Juliett | 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 | Stop immediately. |
| M | Mike | My vessel is stopped and making no way through the water. |
| N | November | Negative. |
| O | Oscar | Man overboard. |
| P | Papa | The "Blue Peter": in harbour, everyone should report on board as the vessel is about to sail. |
| Q | Quebec | My vessel is "healthy" and I request free pratique. |
| R | Romeo | No meaning when flown alone. |
| S | Sierra | I am operating astern propulsion. |
| T | Tango | Keep clear of me. |
| U | Uniform | You are running into danger. |
| V | Victor | I require assistance. |
| W | Whiskey | 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. |
How nautical flags are used
Ships use the flags in three ways. A single flag sends an urgent, standard message, such as O for "Man overboard". Two or three flags together form codes listed in the International Code of Signals book, so ships that do not share a language can still understand each other. And on holidays ships "dress overall", stringing all the flags from bow to stern purely for decoration.
Spelling a name in nautical flags is popular for boat names, nursery walls, wedding signs and beach-house decor. Remember that a real sailor reading your flags sees the single-flag meanings too: a banner that ends in V says "I require assistance".
Limits of this tool
- It shows the 26 letter flags. The ten numeral pennants and the substitute flags are not included, so numbers and punctuation are skipped.
- Colors are standard red, blue, yellow, black and white; printed and sewn flags vary in shade.
- The flags are drawn with the hoist (the side on the pole) on the left, the way they appear in most charts.
How we tested
We checked the design and the single-flag meaning of all 26 flags against the Wikipedia article "International maritime signal flags" and looked at every drawing in the chart. "Sea Breeze" gave S, E, A and B, R, E, E, Z, E with words kept whole, and the saved image (892 × 704 px) showed the same flags, including the swallowtails on A and B. We ran the page in Chromium at desktop width and at 375 px: no sideways scrolling and no console errors. Not tested yet: Safari on iPhone and Firefox.
Questions
What is the nautical flag alphabet?
The 26 letter flags of the International Code of Signals, one for each letter from A (Alfa) to Z (Zulu). Each has its own colors and pattern so it can be read from far away.
Which nautical flag means man overboard?
The O (Oscar) flag, divided diagonally into red and yellow.
What does the diver down flag look like?
In the International Code of Signals it is the A (Alfa) flag: white at the pole side and blue at the end, with a swallowtail cut. In the United States, recreational divers also use a separate red flag with a white diagonal stripe.
What is the Blue Peter?
The P (Papa) flag, blue with a white square. In harbour it tells the crew that the ship is about to sail and everyone should come on board.
Are nautical flags the same as semaphore?
No. Nautical flags are hung on a line, one flag per letter. Semaphore uses one person holding two flags and changing arm positions for each letter.