Rescuers question what3words' use in emergencies

I have this app in my phone, as does my wife. The one time we did have to call the Rescue for a walker in recent years, my wife used the OS locate app instead, giving the MRT a UK grid reference.

I wonder what others experiences are?


Hi Fraser

Never needed to use the W3W on a rescue situation on the mountains but it has came in handy with AA roadside recovery three times in the last 5 months, the app has a navigate tab for Google Maps, VewRanger and few others.
I noticed on one occasion I had to refresh the app several times to get a more accurate location, but apart from that it has been helpful.


What was wrong with all the other coordinate systems? Make me think of this.



I’m not a supporter of W3W.

I think it is wonderful idea in theory but I believe it is a commercial venture and is there to make money - plain and simple. I think he idea has a number of flaws:-

You need an app to ‘decode’ the 3 words of your position and many of the words can easily be confused, misspelt on misheard.

Like positions based on latitude and longitude the Ordnance Survey Grid Reference syatem ihas been around for an awful long time. The grid reference system relies on numbers - which are easily understood and difficult to muddle up, mispronounce or mishear.

I presume you’d still need a map to ascertain the direction and type of ground you are covering if you were looking for w3w positions.

As the mountain rescue teams have commented it appears that its possible to introduce many errors into any particular 3 word positioning system.

The OS system is well known, requires no apps, and the OS Locate App will give you an accurate position if you don’t have a map or if you don’t know how to give a a 6 figure grid reference.

I think the W3W is a nice idea in theory, but fails as it is not too reliable in practice and I see no point in replacing a widely known, tried and tested system.



It’s bad in so many ways.

Primarily it’s just a commercial business being touted as a brilliant way to save lives. They have a massive PR campaign running. Analysis shows many problems.

You need their app and it and the data is not open.
The words are not chosen to sound different, they have used plurals and homophones.
Neighbouring places have vastly different names, you cannot tell if 2 locations are near to each other.
The words are not neutral between languages.
If you want to give a W3W location in your app website, you have to use their system to get the references, you cannot use your own version.

My favourite clone was WhatThreeF**ks which used swear words for location.

The biggest clone which was available with an explanation of the algorithm was WhatFreeWords. But due to the aggressive lawyers involved, the authors never revealed their ID and like all competing systems has been taken off line. It’s still available if you know where to look but you wont find it with Google. Of course, if W3W was not purely a commercial venture but a real way to save lives, this perfect clone would not have been driven off the web.


Ah, the annual W3W PR campaign begins. At one point the MT received a request to add W3W for summit locations. At the same time, SMP received a request to do the same from a different member of the public. Maybe it was a coincidence, but the timings were very close, and a bunch of other press releases came about the same time.

I can’t imagine they’re making lots of money out of this.

I do wonder how it can generate any income, unless they’re selling your location and generally snooping.

Anyway, it seems like a resounding “No!” from the SOTA walking/hiking/mountaineering community.

The lack of any link between the words used for adjacent locations could surely be seen as a strength. The mountain rescue article referenced shows just how easy it was to spot incorrect locations. I can’t imagine that they all set off for a location in Vietnam.

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Except there were examples further down where two locations a few kilometres apart differed by one word being plural and the other singular.

I doubt they set off for Vietnam, but I doubt they immediately set off for the right location either.

Any form of position identification is prone to errors or misunderstanding. If you have to start spelling out what3words phonetically then it loses some of its advantages over other geo-location methods.

It also relies on an electronic device to tell you your position. I can look at a map and determine my position without any batteries (though I might not be able to relay that position to the emergency services :wink:).

I think the weakness in this is nothing to do with ambiguity but rather navigation. If I hear a Lat and Long and know my own I can easily assess whether the other person is N, S, E or W of me. I live in a village where our ancestors thought it would be nice to give every house a name rather than a number. The owners of the first house are forever helping delivery drivers find the right address.

It’s a failure of an encoding system, surely, where the number of possible combinations in the code is much greater than the number actually required, yet introduces ambiguity depending on whether the pronunciation of a word makes it a different word or not, and where plurals are allowed, the all important letter making it plural is rarely pronounced clearly by many English speakers. Then there are English as second (or third) language speakers, more accents etc. Introduce Asian language speakers and the s often disappears because they don’t use that kind of plural ending in their languages.

Number of potential values of a three word combination, assuming each word is 6 characters is 26**18. This is a very large number.

Yet lat/lon to 5 decimal places requires only 9 characters for lat and 9 for lon, including two signs, so it’s really 8 + 8 numeric digits, with limits on latitude (highest value 90) and longitude (highest 180). Far more efficient and yet includes built-in validation of some details (you say you’re in England but giving a lat/long that puts you in New Zealand or France?) and simply requires users to learn some basic navigation stuff. The giveaway in terms of motivation is that they are licencing the system to delivery services, so there’s the income stream.

8 character Maidenhead references would be simpler!

Or the “Google Plus Code” which is open source and codes for nearby locations are similar.

In my opinion commercially-driven gimmicks like this are a distraction. People should be encouraged to learn real long-lived skills such as reading a map. If you search on Youtube, for example, there are plenty of videos to help. For the UK this OSGB play list looks very good (for sure the two clips on grid references are plenty clear):


As a direct recipient of W3W locations on UK Mountain Rescues (I am one of a group of Incident Commanders for my team) I can say this is a big distraction. It produces useful info less than 50% of the time. It has a “guess the mistake” feature to try to fix spelling errors, but this rarely works out a local location.
We will pretty much always send you a SARLOC or PhoneFind. This is a text message with a weblink. The website asks your phone for its location (you have to “allow” that) and it plots it straight back onto an OS map we can see. No transcribing numbers or words… just click the link, give permission for location to be shared and you are done. This almost always works, except when people are stressed and fail to allow permission for the website to access locations. We usually coach them through it on a second try.

To be honest, this should all go away soon.
If every Emergency Services control room gets their systems updated to use Advanced Mobile Location then the vast majority of calls from a mobile will be automatically geolocated.
We get it now from North Wales Police. It simply works and we can ignore the garbage that comes out of badly transcribed W3W.

See the link below for details on AML. The functionality is in pretty much any Android or iOS phone sold in the last few years. Ignore the fact that this is an EU project. UK was one of the first adopters and it’s been available since 2016.
If you call 999/112 this happens automatically and the user doesn’t have to do anything. Also, you can’t switch it off. If you don’t want the emergency services to know where you are then call another non emergency number. That won’t invoke this process.


I’ve never heard of W3W & after reading the above posts I don’t think I want it.
I’ll just stick to my personal locator beacon which I carry on all my activations.


Let’s not forget that we in the Amateur radio hobby have our own locator system in the Maidenhead Grid locator system and there are plenty of Smartphone Apps that will display that and websites that will indicate the location square, down to a small area depending upon how long a code you use.
This could be “marketed” to the rescue organisations, but may get some objection from the W3W commercial entity.
For average “Joe Public” however, the emergency call Smartphone App that is in use in NSW, Australia (I think linked with Fire emergency usage), not only calls the Emergency services at one button press, but at the same time sends your GPS coordinates (lat / long) as a data call / SMS. The expansion of that App or something like it to cover the world would make more sense to me than using What-Three-Words in my opinion.


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Never let what is sensible be chosen in preference to a hard PR campaign were you can use money to buy persuade people the benefit of your technology even if there is none.

Perhaps we should just poison the value by giving false W3W locations? My W3W location is currently ‘underpants.gusset.chaffing’

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Some good ideas there, Ed.

Re Maidenhead locator codes, I have noticed that one of the location formats in my Garmin GPS62S is MH. Yes it displays the current maidenhead code. (But not enough characters for emergency use, admittedly). Someone in Garmin is a ham.

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Try ///using.chamois.cream

Works for me :grin:


Nobody is going to come looking for you there :joy: