Is there a standard I can follow to tag cave_entrance features with difficulty / danger gradings?
Background
I have recently taken up the task of mapping entrances to cave systems in my local area (Cape Town, South Africa). I have followed up until this point the relatively brief standard that was being used by earlier mappers in the area, which involves using natural=cave_entrance along with fee and access tags only. This seems to align with the wiki.
My concern is that there is a high density of cave systems in the area, and the difficulty presented by these systems varies dramatically from “walk in the park” to others which require technical skills and are genuinely dangerous. A small handful are well known and frequented by casual hikers, and my worry is that if others are displayed in a similar manner, it may mislead hikers as to the difficulty of cave systems in the area. I can back this up anecdotally, as I spend a lot of time hiking in the area and often encounter hikers trying to find “the cave from the videos online” and ending up at the entrances to other, more dangerous systems.
Many local hikers rely on Google Maps to navigate, however others use applications that rely on OSM data, such as All Trails, which now displays more technical systems (that I have added) alongside the prominent “tourist” caves. Whilst I have had other concerns about All Trails communicating difficulty to hikers, this is not their fault as they simply do not have the information to more appropriately display.
Grading
If there is no established way to tag cave system difficulty on OSM, would folks be amenable to implementing one? I know all too well that cave grading is a controversial topic, but I really do think that this is a potential safety concern, generally, but more specifically in areas with a high system density and a significant range in difficulty. Of course, this still relies on tile providers and applications doing a good job relaying this information, but it seems that it has to start from the OSM data itself.
As far as I know there is no common grading system for the difficulty or danger of caves at all. Potentially every cave deeper than a few meters is dangerous and difficulty varies with the different sections of a cave. There are grading systems for certain stretches like narrow or water filled passages but not for general difficulty. Again I’d say creating a general grading system would be very tricky and potentially misleading.
The only thing I could imagine is to divide caves into touristic caves which can be visited by anybody without special equipment and “expert” caves which should only be entered by people who know what they are doing.
There is an undocumented key cave:difficulty but I would be very careful by using other values than easy/tourist or technical/expert. This key may be helpful in the given case anyhow.
Please write up a wiki page for that as “in use”, also mention it on the cave_entrance page & use it.
I’d also suggest adding a Description to the mapped cave tag to say the same thing: “Easy access with no preparation needed” “Extremely dangerous. Not to be attempted without extensive knowledge & special equipment” or similar.
The only one I am aware of that has anything approaching widespread adoption is the British system which grades caves on a scale from 1 (easy) to 5 (extremely difficult). However, it is contentious for precisely the reasons you mention. In any case, I do not think it is used outside of the UK.
Thank you! This is very useful. It seemed appropriate in my mind to have a three-tiered system:
easy (for open surface caves or tourist caves that anybody could relatively safely explore)
medium/challenging (for caves with difficulties such as uncomfortable but simple squeezes or easy climbing pitches that would be suitable for an adventurous hiker to explore)
expert for anything that requires technical skills and/or features serious dangers.
Far from perfect, but it felt to me as if this contained enough information to put people on the right track.
That said, a binary easy/expert system does the job almost as well and addresses the safety concern, so if there is a good reason to stick to that I’m happy to do so.
I’ll do so at the earliest convenience. Thank you for the suggestions!
Well, you know that you are free to use any tag you like. Of course you can use a 3 ore more tiered tagging for cave:difficulty and also document it in the wiki.
I just expressed my own evaluation considering the overconfidence and/or stupidity of many hikers, especially young ones, nowadays worse than before, pushed by social media.
There are increasing numbers of people running into serious problems by simply mountain trekking without proper clothing and/or shoes etc. Imagine these people walk straight into the next cave graded medium/challenging cause they believe they can easily manage with their trekking sandals and smartphone light …
