Flag Semaphore Reference
The two flag arm positions, described as hours on a clock, that signal each letter of the alphabet across open distance.
At a glance
Key facts- Flags
- One in each hand
- Positions
- Arms set to clock hours
- Range
- Line of sight only
- Still used
- Maritime and scouting
Arm positions by letter
26 rows| Letter | Left arm | Right arm |
|---|---|---|
| A | Down (7:30) | Side down |
| B | Left (9:00) | Side down |
| C | Up (10:30) | Side down |
| D | Straight up | Side down |
| E | Side down | Up (1:30) |
| F | Side down | Right (3:00) |
| G | Side down | Down (4:30) |
| H | Left (9:00) | Down (7:30) |
| I | Up (10:30) | Down (7:30) |
| J | Straight up | Right (3:00) |
| K | Straight up | Down (7:30) |
| L | Down (7:30) | Up (1:30) |
| M | Down (7:30) | Right (3:00) |
| N | Down (7:30) | Down (4:30) |
| O | Left (9:00) | Up (10:30) |
| P | Straight up | Left (9:00) |
| Q | Left (9:00) | Up (1:30) |
| R | Left (9:00) | Right (3:00) |
| S | Left (9:00) | Down (4:30) |
| T | Up (10:30) | Straight up |
| U | Up (10:30) | Up (1:30) |
| V | Straight up | Down (4:30) |
| W | Right (3:00) | Up (1:30) |
| X | Down (4:30) | Up (1:30) |
| Y | Up (10:30) | Right (3:00) |
| Z | Down (4:30) | Right (3:00) |
Source: International Code of Signals, flag semaphore. This table has not been re-verified against the primary source; see the methodology for what that means and how to report a correction. 26 rows, dataset version 1.0.0. Changelog and JSON.
Where it comes from
Flag semaphore was developed for line of sight signaling in the age before radio, when ships and shore stations needed to pass messages that a telescope could read. A signaller holds a flag in each hand and sets the two arms to fixed angles, one distinct pair for each letter. The system survives today in the maritime service and in scouting, where it is taught as a simple, equipment light way to signal over a field or between boats.
How to use it
Think of each arm as the hand of a clock, pointing to a whole hour, with the flags making the angles easy to read from far away. The positions below give each arm as a clock direction, where 6 o'clock is straight down at your side and the hours run clockwise. Letters A to G reuse a fixed low arm while the other sweeps round, which makes the early alphabet the easiest to learn first. Numbers reuse the letter positions after a numeric sign, so the same shapes serve twice.
This page is a standing reference at a fixed URL, built to be linked and cited. The data here is compiled from the international flag semaphore system used in maritime and scouting signaling.