Several MR teams have suggested that they would rather not use it as it considerably slows them down, there was even an example in the press recently where a MR team went 3 miles the 'wrong side of a mountain' due to 'what3words'.
Many teams are suggesting that as the UK has such a good (OS) mapping system that we should use either map references or GPS, the problem is the 'lets go out on the mountain for a walk brigade' who have never been taught, or made any effort to learn to navigate and have grown up with the 'phone is the answer to everything' philosophy.
A 'middle of the road' review :
https://peaksandlines.com/blog/posts/location-location-location/However, What3Words’s success has prompted mountain rescuers to warn that it may slow searches in the Scottish hills. They advised people against relying on it. Kevin Mitchell, vice-chairman of Scottish Mountain Rescue, said: “It’s a fantastic idea and for areas of the world where there is not a really good mapping service like we have it’s absolutely brilliant. But in this country, with the Ordnance Survey,...……………….
https://www.thetimes.co.uk/article/what3words-app-slows-us-down-say-mountain-rescue-crews-c25fgh3h2A problem identified by one of the emergency services :
……. Take a look at the words again; - storming.blockages.sensuality. Because they are words, you may well think they are easily remembered and, in the event of tending to someone who is unconscious, you may look away believing yourself to have memorised them whilst simultaneously dialling 112/999 and giving CPR. Do it yourself right now; - look away now and repeat the words out loud to yourself. Humans are not used to using words out of context and the tendency is to naturally try to put them into the context of a meaningful sentence. You might therefore remember and pass on to the emergency services something like storm.blocks.sensuality which is in fact located in Canada. See how many attempts it takes for you to repeat the correct words when looking away and then think what it would be like if the pressure was on in a real live emergency. This will be exacerbated by the emergency services’ call taker asking you to spell the words; - extra time, confusion and even more pressure. Those behind the promotion of what3words for this purpose will tell you that they have covered that eventuality so that if you get the code wrong it will be very obviously in the wrong area. But what then? You will have to start all over again; - more time, more confusion and more pressure...…………..