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Comment by saiya-jin | Hacker News Reader

Cave diving ain't safe in any meaningful way. You just try to get best at this activity, minimize the known risks, and for the parts you have no control of, just hope for the best. Plenty of folks, very experienced and well equipped, die doing it every year.

A bit like mountaineering I would say.

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I love how menacing / spooky this common sign is:

https://upload.wikimedia.org/wikipedia/commons/5/56/Vortex_S...

I like the straightforwardness of it. There's no euphemisms, no soft language, no sugar coating. It's just straight up, 'stop or probable death'. It's rare to see such blunt signage in general these days.

Almost all death signs are pretty blunt.

Not so much. They tend to use phrases such as, 'warning extreme hazard, enter at own risk' or 'risk of serious injury or death ahead' or something along those lines. Much more 'lawyer-talky'. This is very blunt and direct by comparison.

It’s also a bit unsettling that, despite the very blunt message of the sign, the Grim Reaper is summoning you to proceed.

well he has a bit different agenda compared to most living folks

That's not blunt, this is blunt:

https://www.reddit.com/r/ScarySigns/comments/c3ujlc/over_dra...

I mean, the warning about cave diving doesn't show you how you'll die, does it?

A bit more info.

"Safe cave diving" was coined by Tom Mount in 1976 as an attempt to educate divers about less dangerous ways of diving.

The ICURR has a slide deck discussing various statistics at http://www.iucrr.org/fatalities.pdf

Anecdotally most of my friends that died in caves died from hypoxia caused by rebreather operation, not from the hard ceiling itself.

Wow, 36% carried no lights at all? I've only been cenote diving but can't imagine doing it without a light.

I'd love to read more of people using underwater drones. Smaller-than-a-football kind of drones. To boldly go where no modern human has fit before.

I imagine building out supply lines for refueling, developing sophisticated position tracking methodologies, and lots of other neat problem solving with no risk to human life.

I thought about this a lot while cavern diving in Mexico. It would likely need to be fully autonomous. Radio penetration is just about nothing in caves and lines get tangled. There are also dry sections in some caves, so you'll need a robot that can climb or fly. Super interesting challenges. I'll take a wild stab that human exploration of underwater caves will be over in 20 years.

> It would likely need to be fully autonomous.

It seems a lot could be accomplished with a tethered probe. A tether solves a couple of problems, namely power and data retrival. Granted, a tethered probe is unlikely to climb or fly.

Tethered probes aren't viable for cave exploration. The tether would get blown around by the water and snag on everything. Human cave divers have to keep their guidelines taut and tie them off periodically to rocks. Probes don't have enough manipulator dexterity to do that in a cave environment.

Tethers also get tangled and will probably hit a bunch of crap you don't want to be hitting.

Could be done with a snaking wire/tube. Battery could be housed at the source. Would need ability to make it through dry parts and go in reverse, but should be physically feasible. Financially is another story

Couldn't you just pull it back to go in reverse?

Every try pulling on a garden hose that's stuck on a table leg, stump, or something else along those lines?

I actually work with underwater ROVs, and in general, I think that this sort of a thing is a long way away. For one, most vehicles that small use an onboard battery, and it is really easy to burn that capacity if there's even a slight current. Plus, cables themselves have a large amount of drag, which means that for any distance, the thrusters that can move an ROV under short-distance conditions quickly become under-powered as any flow takes that cable.

Even if they could be fully autonomous, there's still a bunch of issues, since caves in general and submerged ones in particular are GPS-denied environments. Acoustics like USBL equipment probably wouldn't work in a cave, instances of underwater VSLAM are still pretty nascent, and inertial navigation system with a low-enough error accumulation rate are almost universally export-controlled by their respective countries.

It's definitely an interesting problem, though, and I honestly think that progress in the area is going to be made because folks that aren't experts in caving end up getting interested in it. For example, I'd imagine this kind of a problem is something that space agencies are also really interested in, since there's a lot room in the middle of their respective Venn diagrams.

One such drone is the Sunfish https://www.discovermagazine.com/technology/this-ai-guided-d...

Stone's DepthX AUV is a fully autonomous unit that was intended as a proof of concept for mapping Jupiter's moon Europa. https://stoneaerospace.com/depthx/

I once saw a show on iceberg cave diving. It was similar to regular underwater cave diving except that the “cave” can shift and flip while you’re inside it.

While I'm not a cave diver myself, with proper training and equipment it's possible to eliminate virtually all of the risk.

https://www.gue.com/diver-training/explore-gue-courses/cave

There are many different types of caves, and some can be relative safe with multiple exists and a lot of space to move in.

That said, proper training and equipment can not eliminate a lot of the risk involved. Equipment can always fail, people can get stuck, and the environment is often such that a single minor wrong movement will causes clear water to become instantly zero visibility. Diving in old mines has also risk of collapse and unless you are diving rebreather you are also introducing new air into the environment.

Exploring a new unexplored mine like the one in the article is risky even for the most trained and well equipped divers.

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