Three signals to memorize. That's it. If you only ever learn three things in Morse code, learn these:
The three you have to know
| Signal | Morse | Meaning |
|---|---|---|
| SOS | ... --- ... | Universal distress — "I need help, send rescue" |
| MAYDAY | -- .- -.-- -.. .- -.-- | Voice distress; in Morse, SOS is more common |
| HELP | .... . .-.. .--. | General "help" message |
How to send it without a radio
With a flashlight
- Short flash = dot (one count).
- Long flash = dash (three counts).
- Pause between signals = one count.
- Pause between letters = three counts.
- Pause between words = seven counts.
For SOS: flash flash flash · long long long · flash flash flash. Pause for several seconds. Repeat.
Modern smartphones often have an SOS-flashlight built in (iOS: Control Center → Flashlight long-press; Android varies by device). It pulses this exact pattern.
With a whistle
Same rhythm. Three short blasts, three long blasts, three short blasts. The international mountaineering distress signal is also six blasts in a minute, repeating — but SOS rhythm is recognized worldwide.
With sound (banging on pipes, hulls, etc.)
Hit a hard object three times quickly, then three times slowly (longer pause between each), then three times quickly. Pause. Repeat. Travelers stuck in elevators, ships' hulls, mines, and avalanches have been rescued this way.
Body or visual signs
Carve the letters "SOS" into snow or sand — large, visible from the air. Aviation pilots scanning for survivors look for it. The letters by themselves don't require Morse knowledge to recognize.
Useful phrases
If you have the time and energy to send more, these are worth memorizing in dot/dash:
- I AM SAFE — .. / .- -- / ... .- ..-. .
- NEED WATER — -. . . -.. / .-- .- - . .-.
- NEED HELP — -. . . -.. / .... . .-.. .--.
- WAIT HERE — .-- .- .. - / .... . .-. .
You can preview any of these on the translator with audio playback.
What NOT to do
- Don't keep transmitting once you've been acknowledged or you see help — let other channels work.
- Don't send false distress signals as a test. False alarms are punishable by law in most countries and divert rescue resources.
- Don't worry about being slow. A clearly-sent slow SOS gets through; a fast garbled one doesn't.
Print this
The printable Morse chart is designed to print on one page in either light or dark mode. Stash a copy in your camping kit, glovebox, or first-aid bag. The whole International Morse Code is 36 letters and 10 digits — pre-printed is faster than memorized when you're under stress.