Experience needed before CCR

[Mark Chase]

Ok. So lots of talk about levels of experience in the water etc, but Rebreathers are fairly complex to maintain when compared to o/c

So what about a persons pratical abilities? Should a person that "cannot change a lightbulb" be diving a rebreather

It's ok passing mod 1 with your instructor helping with basic assembly etc, but living with a rebreather is a bit different. The units require upkeep and maintainence, and a certain level of competence is needed

A very good friend of mine recently sold his unit because he found the upkeep just too demanding. At least he realised and excepted this. There are divers out there with poorly maintained units and they are just not aware.

Anyone thinking about moving to CCR ought to be thinking about, and, made aware of what's involved in CCR ownership

You only have to look at the "Recreational Rebreathers" comming into the market to see the efforts been made to make them "idiot proof"

Paul

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I kind of agree but the most frustrating thing about diving CCR is maintaining the first stages on my OC bailout, not using them results in regular failure it seems.

I do feel diving in general needs a practical mind set

ATB

Mark

 

[lizardland]

It comes down to this. 8 years and (doing a rough count since my last proper count) 1630 hours on CCR and total forced bailouts 3. two floods and one failed dill on which I finished the dive back on CCR. So total unrecoverable dives on CCR 2.00

On both occasions I was well aware the issue was building before it became terminal

On one occasion following a total unit flood and failure of HUD and all three cells (rEvo) I could recover the loop and go pure o2 CCR or SCR if needs be

So in total for unrecoverable loops in 1630 hours under water 1 dive


I fancy those odds for my cave diving.


Its voodoo of course as my big catastrophe may be on my next dive and i am aware of this, but my trust is what i can fall back on and this allows me to enjoy cave diving.

I have done some very minor cave diving on OC (Billingshurst cave in Gozo that sort of thing) and I didn't find it fun. On CCR I find it fun.


Its that one thing of having loads of time. I find time to be both very relaxing and very stressful depending on which end I am approaching it.

I liken it to driving through Cornwall with a 1/4 tank of petrol at midnight. I am aware a 1/4 tank will do me 50 miles, I am pretty sure i am going to find an open petrol station in the next 50 miles but its Cornwall and its midnight and the chance i may end up stranded at the roadside with no petrol makes me feel uncomfortable.

Same drive, full tank of gas and I'm chilled out.

Obviously i could break down but i drive a new ish car and a good one so that small possibility doesn't bother me.


Thats the difference between OC cave and CCR cave for me.


OC bailout in a cave? I don't have to enjoy it i just have to survive it. Different set of parameters.



And please guys and girls. I am not trying to convince any one to have an epiphany on this i am just explaining why for me, Cave = CCR.

ATB

Mark

Fair enough, for just doing the tourist tunnels in Mexico once in a while it doesnt really make a lot of difference.

For anyone wanting to cave dive regularly and in a variety of conditions I really think OC first and work up is a much better plan.

To use your analogy, you could do the drive to Cornwall in an HGV or a Yaris. Both will get you there, depending on what you are trying to do then one choice is completely overkill.

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[Mark Chase]

Fair enough, for just doing the tourist tunnels in Mexico once in a while it doesnt really make a lot of difference.

For anyone wanting to cave dive regularly and in a variety of conditions I really think OC first and work up is a much better plan.

To use your analogy, you could do the drive to Cornwall in an HGV or a Yaris. Both will get you there, depending on what you are trying to do then one choice is completely overkill.

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Lets face it the tourist caves in France Florider and Mexico sums up 90% of cave divers out there.

Ironicly I could imagine doing a OC dive in france as theres little chance of getting lost as navigation in the caves is prety simple

In a low viz UK sump situation id probably want a CCR with a CCR for bailout before you could get me in the water without a gun to my head.




Actualy no, come to think of it youd still need the gun

ATB

Mark

 

[lizardland]

Lets face it the tourist caves in France Florider and Mexico sums up 90% of cave divers out there.

Ironicly I could imagine doing a OC dive in france as theres little chance of getting lost as navigation in the caves is prety simple

In a low viz UK sump situation id probably want a CCR with a CCR for bailout before you could get me in the water without a gun to my head.




Actualy no, come to think of it youd still need the gun

ATB

Mark

Even in France you either limit yourself or make life incredibly hard for yourself by diving CCR. I hardly ever even bother taking a rebreather now unless I'm mix diving. I'd say a good 60% at least are not particularly suited to CCR and there are a good few caves showing signs of damage from dragging stages through unnecessarily.

The mistake I think a lot of people make is just looking at it in terms of OC/CCR rather than picking the right tool. It is no different to the decision of drysuit vs wetsuit. You dont deliberately freeze your cock off because you're a wetsuit diver and wont use anything else.

The comment about navigation has to be one of the most arrogant things I've read in a while. I'm hoping that is just beginner's bravado.

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[matt]

The mistake I think a lot of people make is just looking at it in terms of OC/CCR rather than picking the right tool.

Perhaps you could give your analysis as to why you think CCR isn't suited to proper cave diving (I'm not talking about anything with any dry section - only diving!). Genuine question - just interested. Cave hours = 0.

Matt.

 

[lizardland]

Perhaps you could give your analysis as to why you think CCR isn't suited to proper cave diving (I'm not talking about anything with any dry section - only diving!). Genuine question - just interested. Cave hours = 0.

Matt.

A few examples: some very easy (and entertaining) shallow caves mean CCR and bailout for dives easily done on a small twinset; passage that is comfortable on a pair of cylinders gets awkward with a box and stage (and some are getting very battered through unnecessary stage use); plenty of easy caves that are a long walk, it's even longer when you start carting a stage or two; minor squeezes can become very risky on a CCR with front lungs (I saw someone nearly drown in a "beginner" cave when they couldnt exhale into loop properly or reach bailout).

My own bugbear is that you never get a true feel for a place until you dive it OC. You can do all the calcs you like for how long a bailout bottle will last but if you've nothing to baseline it against then you end up either over-egging it a lot or worse dramatically underdoing it.

The thought of risking a CO2 hit for a dive easily done with relatively low risk just strikes me as mad. Doesnt bother me in open water so much but with a roof over your head it's a different game. A hit and an hour swim is one of the hardest things I've done underwater, both mentally and physically. Add on all the other stuff that can aggravate it (I also had a primary light failure on way out).

I think the DIR mantra of looking at CCR when you reach OC's limits really rings true for cave diving. It's a tool that needs used right.

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[Dave Sutton]

I think the DIR mantra of looking at CCR when you reach OC's limits really rings true for cave diving. It's a tool that needs used right.

^^^^^^^^^^^^ Bingo.

Once the tools are each mastered, bring the right one out for the days task at hand.

OC = Simple and task load lowering. A pleasure to dive in the common caves that most of us really dive most of the time. Did three weeks in Florida last year, dove every day, dove OC, and the workload reduction all in all was well worth the change.

But with that said, CCR proficiency for the big dives needs to be obtained with loads of experience on small dives, so.... this season: It's CC to the caves. Not because it's needed in 2012, it's because of 2014.


Dave


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Dave

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[matt]

I think the DIR mantra of looking at CCR when you reach OC's limits really rings true for cave diving. It's a tool that needs used right.

Theory sounds good - just a few personal observations.

I don't dive OC any more - I did 15 years OC in various set-ups but for the last 10 it's only CCR.

I don't yet do cave, and I'm not interested in wriggling though holes like you describe, but if I did a course and some caverns then I would do it CCR if at all.

This is nothing to do with the kit. My head is CCR now and I could not make it toggle like that (not enough practice - just a hobby for me).

I guess if you're using both all the time then this is not an issue!

Cheers
Matt.

 

[Baron015]

First steps / Noobs forum and it's gone all Cave Diving again. I am guessing that for the majority, cave diving is not a priority.

So making decisions or recommendations to the Noobs forum about how best to get started on CCR based on what would best for rock hard 'non-tourist' caves probably doesn't suit the majority either.

Just an observation.

Tb.

 

[Mark Chase]

Even in France you either limit yourself or make life incredibly hard for yourself by diving CCR. I hardly ever even bother taking a rebreather now unless I'm mix diving. I'd say a good 60% at least are not particularly suited to CCR and there are a good few caves showing signs of damage from dragging stages through unnecessarily.

The mistake I think a lot of people make is just looking at it in terms of OC/CCR rather than picking the right tool. It is no different to the decision of drysuit vs wetsuit. You dont deliberately freeze your cock off because you're a wetsuit diver and wont use anything else.

The comment about navigation has to be one of the most arrogant things I've read in a while. I'm hoping that is just beginner's bravado.

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Apolagies if thats wrong

When we tried to do our cave course in France our chosen instructor said it was pointless as the French caves offered little opertunity for learning navigation skills.

He said a couple of the famous ones were little more than a single tunnell in and out


ATB

Mark

 

[Dave Sutton]

First steps / Noobs forum and it's gone all Cave Diving again. I am guessing that for the majority, cave diving is not a priority.

Point noted. Thanks.


Dave

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[Remco]

+10

 

[matt]

I agree.

I also point out there are now almost as many posts complaining about being OT (which is OT in itself) as there are about caves - which at least is diving related....

 

[lizardland]

Apolagies if thats wrong

When we tried to do our cave course in France our chosen instructor said it was pointless as the French caves offered little opertunity for learning navigation skills.

He said a couple of the famous ones were little more than a single tunnell in and out


ATB

Mark

Quite a lot are straight in and out but that doesn't reduce the potential for things going wrong. It's crap for training because it is hard to teach some skills properly but don't equate that with navigation issues disappearing. Why bother with a line if there is only one way out? Should be fairly easy to get out, right?

It's still a 50/50 chance of making the wrong choice when it comes up, there have been plenty of people that have mistaken inwards for outwards when they've been distracted for a second. There is quite a popular cave with sections so big that all you see is blackness with a line going through it, lose your bearings for a moment and it becomes very easy to go the wrong way. Come off the line in some and you'll struggle to refind it as they are so big and there's no way you'll make it out without it. Losing your bearings or getting distracted is suprisingly easy, it's not the first time that I've dropped a stage or something, looked up and had to think which way was which. French line laying also leaves a lot to be desired too, might be one way out but it's not unusual to see 2 or 3 lines (or more) going in different directions.

IIRC Mike Gadd posted a very entertaining report of losing his bearings in the head pool of a cave on deco and nearly copping it. I think it was Clare or JohnG (apologies to either if it wasn't) that did a post on DIRX on completely missing an onward route in a simple in/out cave. I was on a dive where someone (I won't name him, but a diver that's done a fair bit of stuff in the 180-200m range) almost died from a navigation error in about 8m of water in a cave that is used by French trainees for beginner courses. I nearly copped it in a simple straight tunnel through a mistake that screwed up being able to navigate out. I could go on. You need to do enough cave diving to experience just how insignificant things end up getting magnified far beyond what you'd expect. When you start assuming that you can do things differently because a cave is easier is sending you down a really risky road, complacency has a very poor record.

Feel free to reassign to a more appropriate thread

 

[Paul S]

(An attempt to bring this back to a noob topic although maybe it should be separarate)

I think the DIR mantra of looking at CCR when you reach OC's limits really rings true for cave diving. It's a tool that needs used right.

As someone who's looking at starting their journey on CCR soon, this is something I'm struggling with. I'm starting because there are dives I want to do where I believe CCR is the right tool for the job and to get to those dives I've got to start sometime.

I also see people struggle with CCRs where they are the wrong tool, but I understand they're diving them to get practise / hours / familiarity / muscle memory. I'll probably do the same, but the notion of CCR for everything isn't sitting right with me at the moment.

Can you strike a balance between OC and CCR? Is it a good idea? or do you really have to commit?

 

[Dave Sutton]

Start with CCR, use it for everything, know that it'll be three steps back and one forward for a while, and accept this as normal. When you are as good with CCR as you are with OC, then you can start choosing the tool of the day.

Plan two or three seasons.

Dave

 

[Clare]

There is a cave in France where one can go around in a circuit at depth. It's a reasonably large dive depending on how you do it,

I first did this particular dive OC in 2006. Six stages, twin 15s, two scooters etc. We then started going a little further.

Moved to RB 80s, took two seasons to get back to this level then went a little further.

Then switched to CCR. Would start with that same dive again. I know the times, the gas volumes required, the profile etc. Only thing new is the equipment - and that is enough. If that is good, we'll head further in again.

Of course we use the CCRs on dives that don't require them to build familiarity. Quarry/shallow skills practice remains a crucial tool in my diving and that of my buddy. Earlier this year we canned a deep dive as my buddy hadn't been in the water for a while and needed to kick off with less than a 65 meter gas dive.

I'll try again to make my point though. Things that we only do when things have gone wrong need to be absolutely solid if they are to work under stress. Thus emergency gear should be familiar and simple and drills practiced until they are second nature. There is little point building 100s of hours on CCR to ensure familiarity with a unit (although this must of course also be done) IF there is insufficient practice on OC to cope with a bailout ascent. Which brings me back to my two points. First, a bailout ascent is harder than a normal OC ascent, yet a lot of divers struggle with these prior to switching to CCR then concentrate on unit specific tasks. And second, whilst divers approaching a new discipline (CCR, cave, trimix) accept that they have something to learn, give them a ticket and within weeks they think they are fine. Even posts on this thread support this view but I regret that diving incidents suggest that they are not.

To answer a couple of OT questions raised, one straight on lead in Ressel is so damn difficult to find that Jason (one of the original explorers) missed it! Lines in that cave and others can be multiple, missing, broken or confusing. Following monofilament fishing line a long way back sure makes you read the tunnel not the line. Poor viz makes this interesting.

Stuart is absolutely bang on that France is less good for teaching complex navigation than Mexico, but it remains the place I have been most baffled with over the years. Add in poorer viz, colder water plus greater depth and you have more challenging diving in my view.

When I learned to cave dive, I had done over 150 dives before I got full cave. I did over 100 dives in one cave before I took a scooter in, and have dived every cave OC before RB bar one ( damned if I was heading to the end of Eagles Nest OC first!). To those who do a one week zero to hero cave class these numbers sound ridiculously conservative but the older guys still thought I was rushing

Take it steady. Build experience. You can bluff all you like but if the shit hits the fan you need solid skills and finding out you don't have them needs to happen on trying dives not the real thing.

 

[Mike Ward]

.... give them a ticket and within weeks they think they are fine.

That'd be me. And the thing giving me the over-confidence is my OC experience. Maybe if I'd started with CCR I'd have built my skills and confidence over the same time period I have open-circuit and that would be better?

Fully accept that skills can be tougher with CCR, but if that's what you've trained for and practised it's what you do.

Anyway, regardless of my opinion, the marketplace will determine the number of people who start with CCR instead of OC.

 

[Mark Chase]

(An attempt to bring this back to a noob topic although maybe it should be separarate)



As someone who's looking at starting their journey on CCR soon, this is something I'm struggling with. I'm starting because there are dives I want to do where I believe CCR is the right tool for the job and to get to those dives I've got to start sometime.

I also see people struggle with CCRs where they are the wrong tool, but I understand they're diving them to get practise / hours / familiarity / muscle memory. I'll probably do the same, but the notion of CCR for everything isn't sitting right with me at the moment.

Can you strike a balance between OC and CCR? Is it a good idea? or do you really have to commit?

It dosent work like this with all divers.

For many you start out with good intentions (like I did) of diving shalow stuff (30m or less) on OC Nitrox and 30m+ on CCR for trimix cost saving.

Then after a while you cant be arsed to dive OC and when you do, you hate it.

For me anyhting UK i dive CCR. If traveling ill dive OC if taking my CCR is too much hassel for the number of planned dives. But I dont like OC any more.

I have a set of twin 7s hardly used past DIRF (in fact i dont think they have been in the water since DIRF) that i planned for shallow stuff but never used.


ATB


Mark

 

[R0ckcrew]

I am in the same camp as Mark..... When I bought my Vision I sold all my OC gear and dived CCR for every dive.. Like Mark I dive OC when abroad, but I by far prefer CCR.. And 8 years later I am still learning.

Tommy