Never used the air bladder myself, though the utility of the thing is plain. I did use the Pathfinder tool in my first run, and built it in the second, but didn't actually use it. I did use a lot of beacons however. For example with extensive cave systems I would drop and name a beacon at the exit. Jellyshroom cave for example. Cave exit markers used their own color to make them easy to find quickly. I had so many beacons out that it was a bit of a mess in the HUD at times.

Bases and vehicles used yellow beacons
Exits used red
Entrances (and lifepods) used orange
Points of interest above the LR* used blue
Below and including the LR* used green

* I used LR as I reckon if you haven't found it you won't know what it is, so no spoilers. But if you have you'll know what I am referring to.

How'd your deep dives go JC?

Animals flee this hell, the hardest stones cannot bear it for long. Only men endure