Thinking again about your question brings be back to survex, but seems you need to be a coder to get it to work (not my forté). 

https://crates.io/crates/survex-dist

Survex does underpin therion, so would always be my go to for some of the data driven questions.

je Trouvé vous sont régulièrement dans le doubs, je suis allé à lons-le-saunier récemment, a lovely part of France with some great swimming lakes! très jaloux

Al.

Sent from Outlook for iOS
From: alastair gott <alastairgott@hotmail.com>
Sent: Thursday, September 4, 2025 10:59:17 PM
To: List for Therion users <therion@speleo.sk>
Cc: eric georges <zar2@wanadoo.fr>
Subject: Re: [Therion] Distance between two survey station
 
Hi Eric, 

Probably best exporting to survex - total time of below including downloading, probably 2mins!?!

In thconfig
Export model -o cavesurvey.3d 

Download survex https://survex.com/download.html , open the .3d File in survex (double click after installation) and select the two points, then the window at the bottom will give you some of the vital statistics.

Something like:
H for horizontal distance - this is the one I suspect your looking for.
L for length
D for depth
^ these are all from memory, give me a day and I’ll get back in the game and be able to tell you for sure.


Al.

Sent from Outlook for iOS
From: Therion <therion-bounces@speleo.sk> on behalf of eric georges via Therion <therion@speleo.sk>
Sent: Thursday, September 4, 2025 9:28:12 PM
To: therion@speleo.sk <therion@speleo.sk>
Cc: eric georges <zar2@wanadoo.fr>
Subject: Re: [Therion] Distance between two survey station
 
Hello,

I'd like to know if there's a method for calculating the distance between two survey station, and also for identifying the shortest path, or even for determining all possible paths.
I think this should be possible using the .slq file.
thanks

Eric Georges