SOS in morse code is ... --- ...

Why SOS?

SOS doesn't stand for "save our souls" — that came later, as a memory aid. It was adopted in 1906 because the rhythm of three dots, three dashes and three dots is unmistakable, easy to send under pressure, and impossible to confuse with ordinary traffic.

How to send it

Sent correctly, SOS is one continuous character with no pauses between the letters — written with an overbar as SOS. Three short flashes, three long, three short. Pause for a few seconds, then repeat. Any light works: a torch, a phone screen, a mirror catching the sun, or a whistle if you'd rather be heard than seen.

SOS letter by letter

S = ... (three dots)

Three quick, evenly spaced beats — the shortest burst in the morse code alphabet that is still unmistakable at distance.

O = --- (three dashes)

Three long signals, each three times the length of a dot. The contrast between the short S and long O is what makes the pattern carry through noise.

Other signals worth knowing

• .... . .-.. .--. — HELP
• -.- — K, "go ahead, I'm listening"
• --... ...-- — 73, "best regards"