Whistle Signals
Edit on GitHubThe whistle code used in mountain rescue: six blasts for distress, three for reply, and how to make a whistle carry.
Whistle Signals
The whistle is the oldest radio in the kit: no batteries, no license, works in a storm. Its codes are standardized enough that any mountaineer anywhere will recognize them.
The distress code
| Signal | Meaning |
|---|---|
| Six blasts, pause, repeat | Distress |
| Three blasts | Reply: “we hear you” |
| One long blast | Attention, not distress |
Six and three are the international mountain convention (three is also the SOS-derived count). Memorize both directions: you may be the one replying.
Making it carry
- Blow full and steady: a whistle is louder when your cheeks are full and the air column is steady.
- Blast from a high spot; sound carries over terrain better from elevation.
- Cup the whistle or blow from a ridge to direct the sound.
- A metal pea whistle carries farther than a plastic one and survives cold better.
Whistle vs beacon
| Situation | Tool |
|---|---|
| Searchers visibly nearby | Whistle |
| Searchers out of sight | Beacon |
| Night, storm, long range | Beacon |
| Confirm a visual sighting | Whistle (three blasts) |
The beacon transmits for hours; the whistle works for one encounter. Use the whistle when you know the window is open, and save the beacon for the long haul.
The reply protocol
If you hear six blasts:
- Reply with three blasts.
- Note the direction.
- Continue replying every minute so the caller can home in.
- Keep the beacon transmitting throughout.
Related pages
- Signaling Techniques for the toolbox
- Search Patterns and Procedure for the searching side
- Pre Trip Checklist for adding the whistle to the pack