PBS Show on Cave Diving

[mccabejc]

Saw a show last night on cave exploration, and part of it involved a team of researchers diving a cave somewhere. At one point they come to an opening that is so tight they need to remove their side-mounted tanks, feed them through first, then wiggle thru the opening. All the while kicking up lots of silt.

Saw another PBS show a while back where a pair of divers, carrying some homemade radio beacons, exploring some underwater springs in Florida, apparently for the first time. They did the same thing, wiggling through incredibly tight openings. As I recall they were at some insane depth (200 ft. or something like that?), and didn't know where or if the spring had an outlet, or they'd have to turn around and come back to where they started. On the surface there were a couple of guys with radio receivers tracking them as they travelled through the underground springs, and it led them thru a restaurant, across a highway, etc.

This raises a lot of questions in my mind, such as:

1. Are you kiddin' me ???!!!

2. Why even consider trying to squeeze thru an opening that small?

3. When you are diving an spring at a depth of 200ft. underground, it's not the same as having a 200 ft. column of water above you, right (in terms of nitrogen ongassing)? If you're in a 6 ft. diameter cavern, it's equivalent to diving in 6ft. of open water, right?

4. If #3 is true, then I'm reasoning that maybe you can stay under forever without worrying about DCI, and are just limited by air supply. Which is why they lug around 3 or 4 tanks with them.

Can somebody explain the logistics of cave diving? Thanks.

 

[Jason B]

This raises a lot of questions in my mind, such as:

1. Are you kiddin' me ???!!!

No

2. Why even consider trying to squeeze thru an opening that small?

To see what is on the other side!

3. When you are diving an spring at a depth of 200ft. underground, it's not the same as having a 200 ft. column of water above you, right (in terms of nitrogen ongassing)? If you're in a 6 ft. diameter cavern, it's equivalent to diving in 6ft. of open water, right?

No. You still have a 200 ft water column above you.

4. If #3 is true, then I'm reasoning that maybe you can stay under forever without worrying about DCI, and are just limited by air supply. Which is why they lug around 3 or 4 tanks with them.

No, can't stay forever, the 3 or 4 tanks (stage bottles) are so they can push further into the system.

 

[detroit diver]

When the WKPP did their 19,000 foot push, the depth was somewhere in the 300 ft range. They had some serious support services, and left the water something like 18 hours after they entered.

 

[mccabejc]

Okay, so you're saying that these folks go into an unknown underground spring/cavern, max. depths of somewhere around 200-300 ft., squeeze into openings barely larger than their butts, and somehow manage to stay alive and not get DCI.

You gotta be kiddin' me.

By the way, what's a "WKPP", and what's a "19,000 foot push"? Was that the guys in Florida with the radios and stuff?

 

[IceDiverInCA]

Okay, so you're saying that these folks go into an unknown underground spring/cavern, max. depths of somewhere around 200-300 ft., squeeze into openings barely larger than their butts, and somehow manage to stay alive and not get DCI.

That's right.

You gotta be kiddin' me.

No.

By the way, what's a "WKPP", and what's a "19,000 foot push"? Was that the guys in Florida with the radios and stuff?

http://www.wkpp.org

 

[PerroneFord]

Okay, so you're saying that these folks go into an unknown underground spring/cavern, max. depths of somewhere around 200-300 ft., squeeze into openings barely larger than their butts, and somehow manage to stay alive and not get DCI.

You gotta be kiddin' me.

By the way, what's a "WKPP", and what's a "19,000 foot push"? Was that the guys in Florida with the radios and stuff?

It's all about DIR...


..running and ducking!!!



(The WKPP is my backyard. It's our local [15 minute drive] diving holes)

 

[Jason B]

Not all cave divers are DIR (throwing rocks at PerroneFord who is running and ducking )

Jason

 

[616fun]

You think that's bad - I was watching a show on the National Geographic Channel yesterday (Expeditions to the Edge) about a team that was exploring a cave and was doing dives to 250 ft on air. Their excuse was that in order to use trimix in the remote regions of New Zealand it would have to be flown in via helicopter everyday.


Needless to say they left one of their team members in 280 ft of water.

Edit: Found the site explaining the episode:
Deadly Cave Dive

Deep under New Zealand's Mt. Arthur, a team of poorly funded yet highly motivated cave divers pit their skills against the uncharted and seemingly bottomless Pearse Cave system. Kieran McKay, and Dave Weaver dive again and again, pushing themselves toward 250 (76 meters), deeper than anyone has ever dared to go in this cave. When complications prove disastrous, will team members make it out alive?

http://www.nationalgeographic.com/channel/expeditionsedge/

 

[PerroneFord]

Not all cave divers are DIR (throwing rocks at PerroneFord who is running and ducking )

Jason

Since you brought this up I'd be interested to know for those who don't subscribe to the DIR principles, how you approach the diving. While I like a lot of the DIR stuff, and to me a lot of it makes sense, it is clearly not the only way to dive technically.

I'd be quite grateful to hear some other thoughts on the subject if not for the purposes of open discussion, at least for my own benefit. If you feel this would be better handled privately, we could take it to PM, but the conversation might benefit others as well.

Thanks

 

[Doc Intrepid]

Okay, so you're saying that these folks go into an unknown underground spring/cavern, max. depths of somewhere around 200-300 ft., squeeze into openings barely larger than their butts, and somehow manage to stay alive and not get DCI.

You gotta be kiddin' me.

By the way, what's a "WKPP", and what's a "19,000 foot push"? Was that the guys in Florida with the radios and stuff?

By the way...

When they do pushes of that caliber, they often use rebreathers to extend their capacity to remain at those depths for lengthy periods; they use scooters to cover distance faster with less physical effort => less CO2 ongassing, gas consumption, etc.; they use argon in drysuits and a habitat which they can climb into for thermal sustainment (eat, drink, etc.) during lengthy decompression; and huge numbers of support divers to place safety stages, extra scooters, facilitate decompression, etc. There are many logistical details to be managed...these are not 'ordinary' cave dives. No cave dives are ordinary, perhaps, but these exceed most in terms of logistics.