SOS in Morse code

Letter by letter

Read aloud: dot dot dot, dash dash dash, dot dot dot.

SOS is not an abbreviation. It was chosen because the pattern is easy to send and hard to mistake. As a distress call it is sent as one unbroken run, three dots, three dashes, three dots, with no pause between the letters, then repeated.

Tap it back

A short tap is a dot, a longer hold is a dash. Pause between letters.

How to send it

• By sound. A short beep for a dot, a beep three times as long for a dash.
• With a flashlight. Short flash, long flash. Keep the light off for the length of three dots between letters.
• By tapping. Taps cannot be long or short, so leave a short pause after a dot and a longer one after a dash, or tap once for a dot and twice quickly for a dash.
• On a bracelet. A round bead for each dot, a long bead for each dash, and a spacer between letters. SOS needs 6 round and 3 long beads.

How long it takes

SOS is 27 timing units long. That is about 6.5 seconds at 5 words per minute, a beginner's pace, and 2.2 seconds at 15.

More to say