Wherefore what3words…

The three-word location system – which divides the entire globe into three-metre squares, each with a unique three-word address – is undoubtedly another tool in the navigation toolbox, but if you’re heading for the hills, don’t forget the more traditional navigation skills. That old-fashioned map and compass might just help you navigate your way out of trouble, avoiding the need to ever call for mountain rescue.

Over the last week in July, a #KnowExactlyWhere campaign ran across social media, supported by the emergency services, to raise awareness of the what3words app, and how it can be used to save precious time, resources and lives in an emergency. But knowing where you are in the mountains might only be part of the story – and waiting in your cold, wet three-metre box for a rescue team to reach you might take hours. How much more fun would it be if you could link a few coordinates together somehow, and create a route for yourself away from being ‘lost’? Sally Seed and Judy Whiteside take a look.

It used to be so simple.

There were two ways to pinpoint any place on the planet – and both were numbers. One used latitudes and longitudes to mark the spot and one used a grid, usually of 1 kilometre squares, and eastings and northings within that grid, to pinpoint a small square on a map.

Ordnance Survey grid references relate to such a grid of one kilometre squares printed on all OS maps, whatever their scale, so a grid reference on a 1:25,000 map will be the same for someone finding it on a 1:50,000 map, or any other scale. All you need to add is the sheet number of the map, which originates from a zero point just off the south west coast of the UK, near the Scilly Isles.

A grid reference gives you a location on the ground and on a map. Someone with basic navigation skills can then read the terrain and features from the map and navigate from one point to another and on to where they want to be.

Grid references work because they’re part of reading maps.

Hiker figure © Andrew Martin. Main image: Compass © Ghinzo. Images via Pixabay

From compass to hand-held, multi-purpose, battery-sucking technology

Once upon a time – before the advent of smartphones and GPS devices and personal locator beacons – map reading and navigation skills were part and parcel of walking in upland areas and walkers learned to use a map and compass or suffer the consequences. Get lost in poor visibility or unfamiliar terrain and you ran the risk of putting yourself in danger or, at best, of following the wrong path and descending into the wrong valley.

If something went wrong, and your location was completely unknown, suffering the consequences often meant that the resulting mountain rescue call-out triggered a protracted search, involving search dogs and several teams over an extensive area, and could take several days.

Even in the 1970s and ’80s, the usual run of things would be that one of your party would find a descent, get to a public phone and call for mountain rescue – who would then work out your most likely position and head out on the hills to find you. It could take many hours.

Then hand-held GPS (Global Positioning System) devices came along.

Mountain lovers and hillwalkers everywhere – ever alert to ways to enhance their outdoor experience – took to carrying these small bricks in their kit. With one of these in your hand, you could work out where you were (give or take 10 metres for military confusion purposes), whatever the visibility, weather or terrain. Combine this technology with reasonable map reading skills and, when trouble struck, all might still be well as you could find yourself on the map and then navigate to reach your destination.

More recently, smartphones with built-in GPS and online mapping have given anyone wanting to explore the hills the reassurance of knowing their location at the touch of a button. No need (the reasoning goes) to buy paper maps or learn to map read at all…

Get lost or stuck now and that same battery power (and a viable mobile phone signal) means you can call for help and, in an ideal world, that smartphone GPS means the mountain rescue team can locate you – and sometimes even talk you down to the right path without their members leaving the rescue base.

Add in the what3words app and anyone with a smartphone can tell the police or mountain rescue exactly where they are without all those long numbers of a grid reference. Simple? Possibly…

But here’s a few things to be aware of, before you set off to wander in the hills, moorlands and mountains:

  • First, you need to have switched on the GPS on your smartphone for any of this location stuff to work. Obviously.
  • Second, mobile signal is notoriously unreliable in upland areas – you might not have to run all the way back down to the nearest call-box any more, but you may have to move some distance, often up.
  • Third, knowing your location is great if you’re just going to phone for help but, if you want to take responsibility and get yourself down safely without mountain rescue volunteers coming out to find you, you need navigation skills, not just location knowledge.
  • And, finally, if you’ve been using your phone to take pictures and as the source of maps throughout a long day in the hills, there might not be much battery left to call for help and pinpoint your location at the end of the day – the very time, statistically, you’re most likely to need it most.

And that’s where we are today – with high rates of call-outs to people who don’t have a map, who are ringing 999 with their last bit of battery power and putting themselves in danger. And we’re still in summer!

Once the nights start drawing in, it’s even more likely to cause serious problems if you don’t have a torch and start using your mobile phone for light too!

But what exactly is what3words and how does it work?

A global network of 57 trillion, three-metre squares, each with a three-word identifier, what3words was developed by Chris Sheldrick – with the help of two pals. Working in the music industry as a live event organiser, he realised how regularly people would get lost trying to find the events.

And putting three-word identifiers into a mobile phone app so anyone can find out where they are, using only their smartphone, is a brilliant idea – his mathematician pal Mohan even created the first three-word algorithm on the back of an envelope, in time-honoured fashion. Rural locations with no street address can suddenly be found and communicated to others, and getting your head round those long strings of grid reference numbers, especially under pressure – is it up then across or across and then up? – is a thing of the past.

There’s no wonder what3words is proving so popular and, to some extent, it is a really useful app for anyone needing to tell someone else (with the same system in place) where they are. Emergency services, road rescue services and even mountain rescuers are using what3words to locate people.

But… (there’s always a ‘but’). What it doesn’t do is help you to navigate and avoid the need for rescue in the first place. And there’s increasing evidence that, in mountainous areas, those three words may not be quite as accurate as you’d thought. Of 22 call-outs involving what3words locations in the Lake District since the beginning of 2020, 18 have been accurate but four have been way out, sometimes more than 500 metres away from the actual location of the caller. In some places, this can mean a different summit or valley altogether – maybe even a different rescue team’s area!

Mountain rescue always recommends you use paper maps and compass and have the skills to use them

Maps don’t have lots of three-metre squares with those three words shown in them and what3words locations don’t give you any clues on how to get from one to another. For example, ///shutting.ended.mingles may be easier to remember than a grid reference and it will certainly tell Patterdale or Keswick MRT where you are (the summit of Helvellyn), but it won’t help you descend safely via a good path under your own steam. Having a map and the skills to read it will show your route options, the steep ground to avoid and features to follow – and everything else you need to get yourself down safely.

We would always encourage people to think about navigation as part of planning their day in the outdoors – not just the ability to identify a static location on a map but the much more active, moving, updating, spatially-aware navigation. And that means having both the equipment and the skills to navigate outdoors. Carrying a compass and a map may seem old-fashioned but they have one huge advantage: they need neither battery power nor mobile signal and a map gives you so much more information.

Mike Margeson, Ops Director for Mountain Rescue England and Wales, and long-serving team member with Duddon & Furness MRT, is also a Mountaineering Instructor and teaches navigation.

‘From the start, I teach people that there will often be times when you don’t exactly know where you are and that’s ok. It doesn’t mean you’re lost – you just don’t know where you are at the moment.

‘You need to learn strategies of relocation to find something you can recognise and do know where it is such as a big feature tarn, a stream or river. Then you can make a new plan. This is why having a map is really critical and fundamental.

‘As for ending up in the wrong valley – we’ve all done it! It’s part of the learning process. And having to stay out the night, when you hadn’t planned to, because you need to wait until it’s light to find your way back down? That’s how you become more proficient.

‘That said, this also raises two important points. First, it’s always good to descend if you can. It will be less windy, less cold and the terrain will be easier lower down in the valley. Second, if you do have to sit it out in the dark, have you got the minimum equipment to make it through the night, albeit uncomfortably? This might mean carrying spare warm layers, that big orange survival bag and some high energy food’.

Of course, we would always advocate anyone going to the hills #knowexactlywhere they are and we would never discourage anyone from discovering the joy of being in the mountains. But, at a time when mountain rescue call-outs are on the increase following lockdown and many inexperienced people are taking to the hills – perhaps even a different demographic entirely to our usual visitors – there are concerns amongst rescue volunteers about the implications of an over-reliance on what3words for knowing where you are – without planning where you’re going.

As Mike sums up, rather more succinctly than us: ‘What3words is one of a number of GPS location methods available for use with a smartphone, all of which might be of assistance but none of which should be relied upon, particularly in the mountains. We would always encourage hill goers to use the traditional navigational tools of map and compass.’

Knowing where you are is great. Knowing how you got there should be part of your day out. And knowing how to get yourself home safely is the best feeling of all. #BeAdventureSmart and make a good day even better.

If you’re interested in learning more about how you can keep yourself safe and navigate your way around the hills, why not check out our selection of books on the subject? And we’ve plenty of tips and hints on how to #BeAdventureSmart on our ‘Stay Safe’ pages, including a downloadable PDF of our safety leaflet.


  1. Richard Warren on August 7, 2020 at 8:22 am

    Fantastic Judy, Sally and Mike M- really sums up the pros and cons very well – will ask for permission to use it on our websites

    • Judy Whiteside on August 7, 2020 at 8:32 am

      Thanks Richard. And yes, please share as widely as you can 😉

  2. David on August 7, 2020 at 10:11 pm

    It would be worth mentioning about registering your phone for the 999 text service. Text calls connect and send much more reliably than voice calls.
    I believe that registering your phone with 999 text also sets it up so that when you send that emergency text a location message is automatically sent as well.

    • Judy Whiteside on August 8, 2020 at 10:27 am

      Hi David. Good point. We do indeed mention this and more detail about how to stay safe in our safety leaflet and elsewhere on the website (linked to in the blog) – we plan to bring different points into future blog posts rather than cover everything all at once 😉 So watch this space

  3. Curon on August 7, 2020 at 11:23 pm

    Do you have stats for how many calls this year were provided with the location as reported by Advance Mobile Location when the emergency call was made?


    The statistics from BT documentation indicates that most calls have an accurate location reported before the call is connected. Is the information made available to mountain rescue teams, as I believe it includes an estimate of accuracy?

    • Ross (Lakes First Aid) on August 8, 2020 at 11:34 pm

      This is an interesting thought Curon. AML has been around since 2017 and, as far as I can tell, all the UK EMS seem to use it. The only thought I had is that, in an outdoor setting, the caller might be phoning from a different location to the casualty if they have had to find a signal first? So AML would pinpoint the caller but they would need to have used W3W or OS Locate first to note down where the casualty is.

  4. Graham T on August 7, 2020 at 11:38 pm

    Planning your route properly with a paper map in the pub the night before a walk is all part of the fun and adventure! And done properly, it will highlight the dangerous parts and calculate timings. I take a GPS and have OS maps & what three words on my phone… but only for emergencies. Sitting in my Midlands house with a good signal, I can watch the W3W locator move endlessly around, rarely landing on my living room and often in the next street. It’s a great idea but not 100% accurate. Close may not be close enough. Don’t trust it on its own!

    • Judy Whiteside on August 8, 2020 at 10:29 am

      Thanks Graham. Good points! And completely agree about the fun of planning your route 😉

  5. […] You can read more about this and safety when out walking from Mountain Rescue England and Wales here. […]

  6. Guy on February 14, 2021 at 5:25 pm

    I just don’t get this or see any advantage to this over current technology, I simply cut and paste my lat/long for a map app on the phone and send it to 999 text. This just seems like a gimmick to me and another app capable of tracking me.

  7. Andy T on June 2, 2021 at 11:08 am

    Google introduced Plus codes a few years back as yet another way to specify a location. Just tap on a point in google maps to set a Dropped Pin and its there in the details. Why so many ways? At least w3w can sometimes make you smile with it’s location which a lat/long has never done

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