Inverted Twins - Cave Agencies

[Mal Bridgeman]

Originally Posted by Mark Powell

Fliping that around it would be interesting to identify an instructor (other than GUE obviously) who would not teach a student in inverts.

Yep ... sort of squashing the solution space from both sides

Given your contacts, are you able to get any insight on that?

TIA
Mal

[MarkP]

Originally Posted by JasonP

But you can't manage all the problems yourself. If you're diving with a manifold, you've got a single point of failure. And if it keeps smacking off the ceiling, there's a real possibility that it might go. It's not like UK open water diving for instance. If you use sidemounts, you're completely self sufficient. And there are plenty of caves in Mexico which have sidemount only passages. The way limestone faults means you get very wide, but very low passages.

The only real advantage of manifolds, as far as I can see, is that they simplify gas sharing.

If you're in an environment where gas sharing isn't a realistic proposition due to space etc., then I suspect a mainfold is a distinct disadvantage.

This view is from a diver who used to use back-mounted indie twins but eventually realised that manifolds made life easier. Were I to venture into a cave or sump I'd learn again.

[JasonP]

Originally Posted by MarkP

The only real advantage of manifolds, as far as I can see, is that they simplify gas sharing.

If you're in an environment where gas sharing isn't a realistic proposition due to space etc., then I suspect a mainfold is a distinct disadvantage.

Manifolds also allow you to save more of your gas in the event of a reg failure, hose, pressure gauge failure.

If you can get thru a gap in backmounts, you can get thru it sharing gas. That's what the 6-7ft hose is for.

Jason

[James The Badger]

I was just thinking about the prosses of managing a post or valve faliure with one team member with inverts:
3 man team are exiting
number 3 has post valve failiure (as yet undiagnosed)
Signals attention to number 2, who turns to assist
number 1 holds facing 2 & 3
Number 3 has tried to shut down inverted valves but can't locate bubbles Problem 1: due to distance from his ears shuts wrong valve down so turns to allow number 2 to assist/diagnose
Problem 2: disturbed silt from roof and bottom increased due to having to turn 360
Problem 3: diver 2 is obstructed by diver 3 legs/body when manipulating valves to assist in diagnosis, more silt kicked
Problem 4: all the team are now facing back into the cave with reduced viz

I just feel this is the sort of situation that good cave training should be eliminating

[MarkP]

Originally Posted by JasonP

Manifolds also allow you to save more of your gas in the event of a reg failure, hose, pressure gauge failure.

If you can get thru a gap in backmounts, you can get thru it sharing gas. That's what the 6-7ft hose is for.

Got any eggs spare?

[JasonP]

Originally Posted by MarkP

Got any eggs spare?

Why? You posted:

"If you're in an environment where gas sharing isn't a realistic proposition due to space etc., then I suspect a mainfold is a distinct disadvantage."

I don't agree. If you can get into the space in a rig with a manifold, there's enough room to share gas.

Jason

[Steve S]

Originally Posted by Mal Bridgeman

I am hardly the most experienced GUE Trained Cave diver[1] ...so this is my own perspective....if I could no longer shutdown my valves conventionally, I would stop diving where a shutdown was an essential skill....(same with deco diving)

One has to be true to one's self .... if you believe that a skill is essential when you learned it .... how can it stop being essential cos you can no longer do it?

Mal

[1] I don't know that there is a concept of a GUE Cave diver.

Interesting insight there mate and of course it's your prerogative to decide whether to dive or not to dive....and how you dive.

As I see it life is full of challenges that must be overcome to get you where you want to be, and if that includes shutting down 'unconventionally' I can't see a problem, but then again I don't 'get it'

James, an interesting scenario and without getting bogged down you're assuming that a diver has to travel from head to arse to see and communicate the problem....if need be the inverter could form a T shape with the buddy, who is then able to see the valves and remain in eye contact with the inverter [assuming the inverter has a movable neck]

Also I'm quite capable of doing helicopter turns in my Force fins without stirring the silt

As I've said in previous threads my shutdown and fault finding procedure is designed to be undertaken without a buddy as I often dive alone, if a buddy can help great, but I don't factor that into it.

Safe diving,
Steve

[Miss Roxy Chablis]

Some of the factors in a Cave environment can be imagined by people who've never been in a cave. Some others - you really need to experience to understand them fully.

On top of that - there's about a dozen different types of Cave - and experiencing a small handful was more than enough for me on our recent Cave 1 course.

It could be argued that the GUE team diving approach is overkill in an open water environment - I don't subscribe to that view - but I can understand people holding it.

If you choose to cave dive with other people as opposed to solo then you really are only as strong as the weakest member of the team, and this style of diving becomes pretty much a necessity IMO. You have to ask yourself - does what I use / choose to do compromise the safety and enjoyment of the people I'm diving with?

I could forsee that a team with inverts, well configured, all on the same page could possibly work with some agreed protocols and proceedures. I don't think this is optimal - but you could make it work

Certainly based on my limited experience - cave Instructors are a good deal more picky about who they accept onto their courses than tech Instructors. With tech couses - generally it all starts shallow and progresses deeper once the Instructor is happy and knows what he's dealing with. With Cave - although you're not doing huge dives to start off with - you can't avoid being in a usually silty environment with no natural light and lots of possibilities to get lost if you screw up. Some people's heads don't like it

I would imagine that there are a few decent Instructors out there who if you satisfied them that you were sensible and had thought things through - would probably be happy with inverts.

Certainly in a Florida / Mexico / France style environment, totally flat trim, excellent buoyancy and a full range of cave style technical fin-strokes are an absolute requirement. If you haven't got these - you'll really struggle.

To be fair to Mal - he's just pointing out stuff that is pretty standard in this type of "non sump" cave diving without being partisan. Non GUE Instructors are usually quite similar to the GUE style of doing things. Our GUE Instructor for Cave 1 had taught for the NACD for ten years before moving over to GUE only two years ago. We asked what he had to change to make the crossover and his reply was almost nothing at all - he teaches much the same stuff now as he did then.

Hope you find someone who can help you and you get as much pleasure out of it as we did

HTH

[Janos]

Originally Posted by James The Badger

I was just thinking about the prosses of managing a post or valve faliure with one team member with inverts:
3 man team are exiting
number 3 has post valve failiure (as yet undiagnosed)
Signals attention to number 2, who turns to assist
number 1 holds facing 2 & 3
Number 3 has tried to shut down inverted valves but can't locate bubbles Problem 1: due to distance from his ears shuts wrong valve down so turns to allow number 2 to assist/diagnose
Problem 2: disturbed silt from roof and bottom increased due to having to turn 360
Problem 3: diver 2 is obstructed by diver 3 legs/body when manipulating valves to assist in diagnosis, more silt kicked
Problem 4: all the team are now facing back into the cave with reduced viz

I just feel this is the sort of situation that good cave training should be eliminating

Run that scenario again with valves-up tanks and number one (the lead diver) having the problem and you have exactly the same issues as you describe.

Touche.

Janos

[NotDeadYet]

Originally Posted by JasonP

I don't agree. If you can get into the space in a rig with a manifold, there's enough room to share gas.

Interesting. I could show you quite a few places where you can get in with a backmounted set but there is absolutely no way you'd be able to share gas. Or shut down the manifold for that matter. Real life is a hell of a lot different to drills, possibly one of the biggest hinderances is getting an out of air signal where divers have restricted movemnt. If you can't turn round how do you signal the diver behind. Remember, your remaining life is being measured in seconds.

One which always amazes me that instructors use for initial cave dives is the Font del Truffe in the Lot. I'd be very surprised if anyone could air share out of sump 2 or the entrance for real.