What is the SOS Signal?
The history, meaning, and proper usage of the universal distress signal: ...---...
Three Dots, Three Dashes, Three Dots
Does SOS stand for "Save Our Souls"?
A common misconception is that SOS stands for "Save Our Souls" or "Save Our Ship". In reality, SOS does not stand for anything.
S is three dots and O is three dashes, but the SOS distress signal is sent as one continuous sequence (...---...). Leave a one-unit gap between each mark, without the three-unit letter gaps that separate ordinary S, O and S characters.
How to Signal SOS
The continuous SOS rhythm is three short marks, three long marks and three short marks, with short internal pauses and no ordinary letter gaps. Use the comparison below to distinguish it from typing the separate letters S, O and S. A browser demonstration teaches the pattern; reception depends on actual equipment and conditions.
- Auditory: Blowing a whistle, tapping a pipe, or honking a horn (three short blasts, three long blasts, three short blasts).
- Visual rhythm: three short flashes, three long flashes and three short flashes, with short internal pauses. The continuous pattern has no ordinary letter gaps. The browser comparison demonstrates timing.
- Physical: Arranging rocks, logs, or brightly colored clothing in the shape of the letters "SOS" on a beach or clearing for aircraft to see.
Practice Transmitting SOS
The main translator encodes the written letters SOS with normal letter gaps. Use it to learn the individual S and O patterns, then compare them with the continuous distress signal shown above. It does not generate a continuous SOS prosign.
Try it in the Translator →Compare continuous SOS with written letters
The continuous distress pattern joins all nine marks with one-unit internal gaps. At 20 WPM it lasts 23 units, or 1.38 seconds, from the first mark to the last. Encoding S, O and S as ordinary letters adds two three-unit letter gaps instead of the corresponding one-unit internal gaps, producing 27 units, or 1.62 seconds.
Continuous signal
...---...Ordinary text encoding
... --- ...The main translator uses the second form when you type SOS. This demonstration lets you hear the difference rather than infer timing from the typography.