HesapHanem

Maritime Signal Flag Lookup

Enter a single flag letter from A to Z.

How it is calculated

This is a table lookup, not a calculation. The input is trimmed and upper-cased, and the tool takes the first letter from A to Z it finds; anything after that letter is ignored. It then returns three items from a built-in table of the 26 International Code of Signals single-letter flags: the meaning of the flag flown alone, the NATO phonetic name (Alfa, Bravo, Charlie and so on) and the letter it matched. Digits, accented letters, symbols and empty input give no result. Only single-letter flags are covered, not numeral pennants, two-letter codes or multi-flag hoists, which carry different meanings.

Worked example

You see a flag with the letter O and want its meaning. Type O (lower case works too). The tool upper-cases it, matches the letter O in its table and returns the meaning "Man overboard.", the phonetic name Oscar and the letter O. The same lookup for X returns X-ray, meaning "Stop carrying out your intentions and watch for my signals." Typing "Oscar" instead would match only its first letter, O, which happens to be right here.

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Common mistakes

  • Typing the phonetic word instead of the letter. "Alfa" returns the A flag, but "Bravo" or "Charlie" return B and C only because the first letter happens to agree, and a word such as "Hotel" would work for H by chance. Enter just the letter.
  • Expecting more than the first letter to be read. "AB" gives the A flag; the B is ignored. Look up each flag separately.
  • Entering a digit (0 to 9) for a numeral pennant. Digits are not in the table, so nothing is returned.
  • Reading a multi-flag hoist as the sum of its letters. This tool gives each flag's meaning when flown alone; combined hoists have their own meanings in the code book.
  • Confusing flag meanings with the Morse or phonetic spelling of a letter. The flag meaning for Q or J is a full message, not the word that starts with that letter.

About this calculator

The International Code of Signals assigns each letter of the alphabet its own distinctively colored and patterned flag, so that ships can communicate short standardized messages visually across open water without a shared spoken language. A single flag flown alone carries a specific urgent meaning — for example, “A” (Alfa) means “I have a diver down; keep well clear at slow speed,” while “O” (Oscar) means “Man overboard.” This tool looks up the ICS meaning and NATO phonetic name for any single letter from A to Z.

Signal flags remain part of standard training for merchant mariners, naval personnel, sailing racers and maritime cadets, who must recognize single-letter flags on sight for safety-critical situations and use flag hoists combined with the phonetic alphabet in radio communication. They're also flown ceremonially and used in yacht racing to signal course changes, postponements and other race-committee instructions.

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  • Editorial team

    The meanings here are for a single flag flown alone. Flags in a multi-flag hoist, numeral pennants and flags shown at a sailing race follow other rules: race committees reuse letters, for example P as the preparatory signal and X for an individual recall at the start. If you see a flag at a regatta, read the sailing instructions first and use this table as a general reference only. Which flags do you find hardest to remember?

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