International Semaphore Alphabet
Encode A-Z text as accessible semaphore diagrams and clock-position pairs, or decode explicit position pairs back to letters.
Convert
Fixed viewpoint: every diagram faces the receiver. Left and right always name the signaller's own arms, so the signaller's right arm appears on your left.
Use ASCII letters A-Z in either case. ASCII whitespace separates words; runs collapse to one boundary and outer whitespace is ignored. Digits, punctuation, emoji, and non-ASCII letters are rejected.
Position-pair builder
Result
Enter text, then choose Encode.
Receiver-view sequence
Pairs list the signaller's left arm first and right arm second. A slash is a word boundary.
A-Z reference
These receiver-view positions follow the semaphore chart in the U.S. Navy Signalman training manual, Appendix II, and are cross-checked against the Australian government Semaphore Flag Signalling System reference.
Convention and limits
Notation
Each token is left-clock,right-clock, using one of eight 45-degree positions: 12:00, 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, or 10:30. Tokens use ASCII whitespace as separators. A standalone slash marks a word boundary. The decoder requires this exact syntax and never guesses swapped or mirrored arms.
Scope
This is a visual signalling alphabet, not encryption. The focused converter supports A-Z only and creates at most 120 letter diagrams. Numeral mode, error, cancel, attention, and other procedure signals are outside its scope. The slash is a textual word marker, not an invented arm pose; naval procedure may call for a FRONT signal between words.
For a known check, CAB is 6:00,10:30 6:00,7:30 6:00,9:00. Real signalling also depends on clear sight, correct facing, trained movement, and an agreed procedure.