How to Give Mountain Rescue Your Exact Location: Grid References, what3words & SOS
Know How to Say Where You Are, Before You Need To
The one outdoor skill you hope you'll never need, but should learn today.
Imagine you're standing on a windswept hillside. A member of your group has slipped, injured an ankle and cannot continue.
You call 999, ask for Police, then Mountain Rescue.
"Can you tell us exactly where you are?"
It is one of the most important questions you will ever be asked outdoors. The good news is that there are several simple ways to answer it, as long as you have practised before you need them.
Straight From Mountain Rescue
We sat down with Mountain Rescue team members to talk through exactly what they need when the call comes in. It is well worth five minutes of your time.
Did You Know?
Modern technology has transformed how Mountain Rescue teams locate casualties.
But it only helps if you know how to share your location clearly and accurately.
Think of It Like This...
Saying you are "near a big hill" is not much help. A rescuer needs something precise.
OS Grid Reference
Your street address.
what3words
Your front door.
Phone Emergency SOS
Dropping a live pin.
Garmin inReach
A two-way conversation with your exact location attached.
The Four Ways to Tell Mountain Rescue Where You Are
1. OS Grid Reference
For Mountain Rescue teams, the Ordnance Survey National Grid remains one of the most useful ways of describing a location.
A six-figure grid reference, together with its two-letter grid square, pinpoints your position to around 100 metres.
NY 246 073
Best for: map users, GPS users and Mountain Rescue teams.
Top tip: Do not wait until you are in thick mist or heavy rain. Find where your GPS displays your grid reference before you leave home.
Practise at home first. Our free UK Grid Reference Finder lets you look up any grid reference on a map from the comfort of your sofa. Use it to get familiar with how grid references work and to check the format before you head out - not as a substitute for knowing how to read it off your own GPS in the field.
Find Your Grid Reference on Your Garmin GPS
Every Garmin GPS is slightly different. These videos show exactly where to find your current OS National Grid Reference.
Garmin GPSMAP 65 / 65s
Garmin GPSMAP 67 / 67i
Garmin GPSMAP H1 / H1i Plus
2. what3words
The free what3words app divides the world into 3-metre squares. Each square has a unique three-word address.
///filled.count.soap
Best for: giving a quick, easy-to-read position from a smartphone.
Important: Use what3words alongside a grid reference whenever possible, not instead of one. Similar-sounding word combinations can exist a long way apart, so read it back carefully, and where you can, back it up with your grid reference. That way a small mishearing can't send a rescue team to the wrong valley.
3. Smartphone Emergency SOS
Modern smartphones are now very capable emergency devices. If you dial 999, the emergency operator may be able to request your location directly.
Many newer Apple iPhones and Android phones also support Emergency SOS via satellite, allowing emergency information to be sent where there is no normal mobile signal.
Mountain Rescue teams may also send a secure SARLOC or PhoneFind link, which allows your phone to send its GPS position back to the rescue team.
Do this before you leave home: register for EmergencySMS by texting the word register to 999. It means you can text the emergency services if you have signal too weak for a call — genuinely useful on the hill, but only if you've set it up in advance.
Best for: emergency use with a compatible smartphone.
Limitations: availability depends on device, country, satellite visibility and phone battery.
4. Garmin inReach
If you regularly walk in remote areas, a dedicated satellite communicator such as a Garmin inReach adds another level of reassurance.
Unlike a mobile phone, an inReach communicates through the Iridium satellite network, allowing two-way satellite messaging where mobile signal is unavailable.
- Trigger an interactive SOS to Garmin Response.
- Send and receive two-way satellite messages.
- Share your live location with family and friends.
- Continue communicating while help is on its way.
Best for: remote hillwalking, backpacking, multi-day routes and areas with unreliable mobile coverage.
Why it matters: two-way messaging means responders can ask about injuries, weather, group size and whether the situation has changed.
If you're weighing up whether an inReach is right for your walking, we stock the full range and can talk you through the models and airtime plans - see the Garmin inReach range at GPS Training.
Which Method Should You Use?
Use whichever gives rescuers the clearest picture of where you are. Better still, give more than one.
| Situation | Best Option |
|---|---|
| Carrying a handheld GPS | OS Grid Reference |
| Smartphone available | what3words and Emergency SOS |
| Remote area with unreliable signal | Garmin inReach |
| Mountain Rescue asks for more information | Give everything you can: grid ref, what3words, phone location or inReach details. |
Think in Layers of Safety
A map, compass, GPS, smartphone and Garmin inReach are not competing tools. They are layers. The more confidently you can use them, the easier it is to stay found, or be found.
Real-World Examples
Open Moorland
Example: The Cheviots
GPS reception is usually good. A grid reference or what3words location normally works well.
Deep Valleys
Example: Borrowdale or Great Langdale
Mobile signal can disappear quickly. Satellite SOS or Garmin inReach becomes particularly valuable.
Dense Forestry
Example: Kielder Forest
Let your GPS settle, cross-check with the map and avoid rushing your location if you are unsure.
What Happens After You Call 999?
Call 999
↓
Ask for Police
↓
Ask for Mountain Rescue
↓
Explain the emergency
↓
Give your location
↓
Keep your phone on
↓
Rescuers navigate to your position
Before Every Walk
Screenshot this list if it helps. It is simple, but it matters.
- Know where your grid reference is displayed on your GPS - practise with our UK Grid Reference Finder.
- Install the what3words app.
- Check Emergency SOS settings on your phone.
- Register for EmergencySMS by texting register to 999 before you need it.
- Carry a paper map and compass.
- Tell someone your route and expected finish time.
- Carry a fully charged phone.
- Take a power bank on longer walks.
- Consider a Garmin inReach for remote areas.
The 10 Minute Challenge
Before your next walk, check you can do the following:
- Find your grid reference.
- Open what3words and read out your location.
- Find Emergency SOS on your phone.
- Send a test message if you own a Garmin inReach.
If you can do that, you are already better prepared than many walkers.
Technology Helps, But Skills Matter Most
Technology has transformed outdoor safety. Paper maps remain invaluable. GPS devices make navigation easier. Smartphones can now share your location in remarkable ways. Dedicated satellite communicators such as Garmin inReach add reassurance when you are beyond mobile coverage.
The important thing is not simply what you carry.
It is knowing how to use it before you need it.
Being findable is an outdoor skill, just like reading a map or using a compass. Spend a little time practising now and you will hopefully never need to rely on it. If you do, you will be very glad you prepared.
Continue Your Outdoor Navigation Training
Technology can tell rescuers where you are. Training gives you the confidence to do it quickly and accurately.
GPS Training Online Resource
Step-by-step videos, guides and support to help you get more confident with your GPS.
Garmin GPS Training Courses
Hands-on training with experienced tutors, helping you use your Garmin properly outdoors.
TwoNav GPS Training Courses
Practical, friendly tuition to help you get the best from your TwoNav GPS.
1:1 Remote Online Training
Personal one-to-one tuition over Zoom, tailored to you and your device from the comfort of home.
Learn the skills before you need them.