GUE RB80 training

[Clare Gledhill]

Cor - well I had to post in this forum at least once didn't I?

Life is a funny old thing. Whilst Janos, Mark and Howard head off to Mexico to do a cave course, I find myself sitting in Florida, contemplating diving a rebreather for the first time.

The rebreather in question is a Halcyon RB80, the course is GUE Rebreather and the students are me, Alastair and Steve Shultz from Canada. All of us are Tech 2 and Cave 2.


Me

It has to be said that it is not a small unit – but that is fitting as it was not a small decision to make. I’ve been agonising about this for eighteen months at least and only finally decided when Al and I chatted to Jarrod in Budapest in December, allowing us the opportunity to discuss the pros and cons of the decision to move. After that decision was made, David Rhea moved heaven and earth to arrange a course for us on the dates we were already due to be in the states to do some cave diving, found a third student and …. Gulp… well the bank balance was taking a serious pounding and we were heading out to the States to see if we had done the right thing.

I suppose the first question that most will ask, is why. Well it is certainly not cost – the unit will never pay for itself in gas savings, even though it is less expensive than some commercially available units any gas savings will only dent the investment we had to make to move over.

Essentially my diving had reached a crossroads. I did some dives last year, both in caves and in the ocean, which were at the very edge of my comfortable open circuit range. Whilst I always believed that my plans were safe, when you are several thousand feet back in a cave at 60 metres and half a stage bottle is lasting not much more than 7 minutes, you do start to question your sanity – even if you are carrying six bottles.



My OC kit for a dive in France in June last year

Without the ability to stage gas in the ocean, I was simply unable to contemplate jumping in with four bottles or more, especially as you need a scooter to swim that number of bottles at depth which would significantly add to the surface burden jumping off the boat. Either I could stay in the 70 metre 3 bottle ocean range and restrict my cave diving indefinitely or I could contemplate extending my diving in both environments in future by moving to rebreather. It was not an easy choice to make but chatting to Jarrod, Michael Waldbrenner, Richard Lundgren and David Rhea and hearing their views helped.

It is worth pointing out that you don’t just decide to buy an RB80. GUE Tech 2 is the minimum requirement for training but meeting this pre-requisite is not enough on its own. GUE and Halcyon really don’t like making them, don’t like running courses and don’t want people to dive them. A decision to move over to the unit is therefore not merely the students, it is one owned by the community – if you are judged to be wanting one for the wrong reasons, or not have the skill level or the right attitude to take on the challenges of the unit, they simply will not agree to manufacture a unit for you or provide training. If training is provided and the student is found not to have reached the level required, they will not be permitted to take the RB80 away with them – one of the gambles that you make when you sign up to purchase a unit. Out of 17 people who took the course last year – all were GUE trained at the highest levels – and only three received a pass. GUE are serious when they say that they really don’t want people diving these things and the course, the standards, and the instructor attitude during training reflects that.



Five days, four of which are spent diving, where we will be riding a vertical learning curve taking us from our first rebreather dive on day two, up to three bottles on day five.

Day one is an all day classroom day where we strip down the unit to component parts. Bear in mind that I made this move reluctantly, and you will understand that I approach the unit with some apprehension. Halcyon have built a rebreather just for training so that students can play with it in the classroom, tearing it down and building it up again to gain through understanding.

It looks complicated at first but then to my delight I find that it is intuitive (a word I guess I’ll use a lot during this write up) and assembly/disassembly, cleaning, servicing are all user friendly and possible in the field. David’s knowledge as a WKPP exploration diver who has been diving the unit since it was first developed, as well as being Mr Scubapro who trains their service technicians, assists us greatly in deftly picking the unit apart so we can really understand how it works and fits together.

The unit’s individual characteristics are discussed in depth. The pros and cons of the unit, why certain decisions have been made in its design, how dive plans can be built, what issues to look out for when diving it although classroom work here will be compounded in the water many times over before the end of the week. No romance at all – this unit is a tool for a job and at every stage we are reminded that we take an increased risk when we dive the unit rather than open circuit and the best dive of all will be one where we don’t have to use it.

Finally, our shiny new units arrive from Halcyon and we sit there reconfiguring regulators, attaching drive hoses and switch blocks, checking we have all that we need to go diving tomorrow. Nerves for all three of us are increasing as none of us have been on a rebreather before – even for 5 minutes in a pool. What will it be like?

We arrive at Blue Grotto early the following day. Units are to be packed with lime and David shows us a few tips on how to do this. I’m pleased that I find that I can assemble the unit with little prompting – again it has been designed to make it intuitive, and my success has little to do with my knowledge retention from the day before and more to do with the simple design. I look over at Al and Steve to find that they are having similar success.

With the unit assembled and in the rack, we connect regs and finally top off with wings and backplates. The kit now looks almost familiar – all my normal clips, regs, my familiar wing and the same backplate which has been with me for almost 1000 dives now. Just this new bit in the middle, the RB, and the switch block to worry about.



I was lent a rack which looked a little battered – guess it has seen a few dives!

We are to jump in, descend open circuit to 6 metres, and then one by one switch to rebreather mode – a process which simply means flipping a lever on the mouthpiece. Al goes first and I’m watching for a change as he does – but there’s nothing. The bubbles have stopped but he is still perfectly flat and his buoyancy is not really moving although he appears to be making fine adjustments. Then Steve switches to rebreather – with the same results.

Then it’s my turn.

Please God don’t let me crash into the bottom. Please don’t let me hate it.

I flip the mouthpiece and the bubbles stop.

I can’t feel myself breathing – I fight for breath and feel very unhappy indeed. Something must be wrong. I flip back to OC.

Calm myself down – OK it wasn’t that bad. Perhaps the others feel like that too. I try again.

OK, let’s think about this. The reason I can’t feel myself breathing is that the air is not cold – a weird feeling which is alien to me but I can’t deny that I am able to breathe. Stick with it.

I have to dump some gas. Damn too much – breath in. Damn that doesn’t work – add gas. Damn too much – dump some. Ah – got it. Nope not got it – drifting up – dump some more. After hundreds of dives being able to put myself anywhere in the water column I have wanted to this is not nice but none of us are moving more than perhaps half a metre. No-one is hitting the bottom, no-one is hitting the surface, we are just working slightly harder than normal to stay still.

We’ve all held horizontal trim too which will assist with team diving later on, back kick and helicopter turns are vitally important in a RB which is the size of a small car without the manoeuvrability.



Alastair

Valve drills are next. Familiarity of procedure and kit is challenged due to the new elements but we all cope relatively well once we each work out where the valves are and how best to get to them. I find myself wondering when it is all going to get difficult as whilst it is uncomfortable due to being different it’s not that bad at the moment.

Now S drills. There is an extra step here, getting rid of the loop with the left hand whilst unclipping the long hose with the right ready to donate as soon as the loop is clear. Anyone who has to use two hands to unclip a regulator will struggle with this procedure, the new step slowed things down but again each of us coped OK.

Finally, we swim around a circuit that David has laid which runs from 3 metres down to 9 metres. At 6 and above we are to be on open circuit, at 6 and below we are to be running on the RB to get used to switching backwards and forwards as well as coping with the buoyancy shifts on the RB which makes lung control useless. Then we ascend for a debrief. My first dive on an RB is over.

Team buoyancy, trim and basic skills are pronounced as sound which David sees as encouraging for the course ahead as it means we can already start to progress.

We drop down again for another hour, where after drills; we head round the circuit where David will cut off the supply of gas to the rebreather through the switchblocks so we can start to pick up those intuitive alarms which we need to dial into to confirm that the unit is working efficiently. When an RB80 stops injecting gas you effectively run out of gas – slowly – with each breath getting a little tighter. If you are not sure whether the unit is injecting, a deep breath will force the injectors to fire, something you can hear and grow to feel.

Round and round we went, dealing with the challenge of ever changing buoyancy and the switchblock was never far from David’s fingers. It started to become familiar both in sensation and in procedure and when three of us experienced failures at the same time we simply switched to OC and took it in turns to identify the failure and fix it. One thing was becoming clear, on a RB with such a simple OC bailout mechanism; there is simply no need to hurry. Switch, signal the team, ID the problem and resolve if possible. Round and round, memories being built and rewired, until an unresolvable failure meant that the team thumbed the dive. David was pleased – we were delighted as we had all prepared for the worst and it had been far from that. Early in the week though – tomorrow we would move to Forty Fathom Grotto and stages.



Wednesday was raining and we arrived at the Grotto early to prep kit. Two stages each were carried down to the quayside many steps below, followed by the units.

For our first dive we were to dive again without stages, to confirm our skills on the unit when directly driven, albeit through the switchblock. More drills followed by a drop to 20 metres into the murk of the grotto where we laid line midwater to ensure that we were not using the bottom as a prop to mask poor buoyancy. We did OK so picked up a stage each and dropped down again.

The switching procedure is simple, IDing gas the way we have been trained, routing the stage hose under the longhose and the light cable so as not to get hung up or foul anything on the dive. The switchblock is very sharp when new and news filing down to avoid many cuts to the fingers. Unfortunately we failed to return to High Springs any day in time to get to the shops before the closed so a file was never available. Our hands show the scars still.

This dive, number four, was when things really started to warm up. Al and I had happily permitted our buddy to switch to a 70 bottle – forgetting that in the US that is the equivalent of 21 metres. The floor of our dive was 20 metres but David sought to force us below this to try to get Steve to breach the label of his gas (all stages were filled with 32 per cent) at one stage physically seeking to push us below the MOD. He failed to do this but only because we had set the floor before the dive – we were unaware that Steve’s gas markings meant that he was potentially on the wrong gas.

We were deservedly torn off a strip for this as a team, as well as other poor/missing markings on bottles. Rental tanks or not, imperial/metric or not, this had to be sorted out before we dived again. We returned back to our hotel angry at ourselves for not coming better prepared to the water and stripped down the units, cleaning and checking every aspect of it ready for the next day’s diving.

Thursday was Valentine’s Day – but nothing romantic about our day at all. Up at 5:30am for a swim test at the Gainesville Health and Fitness Centre and then straight to Forty Fathom Grotto again where the units needed to be checked and repacked.

Two stages today in water, and David ramped up the failures to a point that Al described the course as Tech 2 on steroids. Failure after failure led to stress levels rising and skills being seriously challenged. All of us made the sort of errors that we would not make when stressed, checks missed, miscommunication, attention to detail running below normal levels as we maxed out capacity. I was well outside my comfort level on the second dive, with David riding my manifold whooping all the way to the surface having blown both my valves and continuing the failure during the ascent – alternating between sitting on me during ascent and letting go – with the resulting buoyancy swings. Stress levels rose remarkably – and I let it show which is unacceptable.

We returned home in a sombre mood. Tomorrow was make or break day but the main enemy was not David or the RB itself – the main enemy would be stress.

On Friday the team were given a late start by David as we had all pretty much reached exhaustion point, but we decided to turn up early and get the units built so we could maximise the in water time that day. Each of us would have to carry three stages today, so bottles were marked, checked, regs attached (each with rebreather cheater) and carried down the numerous steps to the water. We were all nearing completion of the unit assembly when David arrived and he was clearly cheered by the timetable gain that this would permit.

The plan that day would be four dives. Two with multiple stages and failures and two short ones to follow on – more of that later.



We jumped in and I happened to be leading the dive so headed down the shot line after completing drills at 9, settling out at 30 metres. It is very disconcerting laying line in midwater. Forty Fathom Grotto has various up lines which loom out of the gloom from time to time allowing you to tie off, but in the main there is simply no reference at all in black water. Laying the line, seeking to maintain compass heading and depth, as well as monitor team for the inevitable failures is challenging although I was sort of getting used to it by the end of the week. There is no reason every to do this in real life but again is used to increase stress levels to see what breaks.

Failure after failure was thrown. First fixable ones where a valve was found to be off or a switchblock hose had popped out etc etc. Then came the non fixable failures. Al lost his left post. We reached the bottom of the shotline and those of us who could switched off the drive bottles. Al remained on his. A short ascent to 24 was made very entertaining by David stealing both Steve’s deco gasses – to the accompanying Steve yelling of ‘Son of a b***h!’ which of course we could now hear.

On arriving at 21 I switched and donated OC deco reg off the same bottle to Steve having established supply for myself through the RB and cheater. Al lost his right post removing the last of his backgas regs so managed a neat stage to stage switch from the RB to OC from his 50 percent bottle. He was then able to tidy away the bottom stage plug the 50 into the RB and switch back to SCR. I put my tided up drive bottle on my leash to clear the front for the O2 later on.

At 9, I switched off the 21 metre bottle and on to back gas through the RB. I grabbed my leash and brought it forward to unclip the O2 and drop off the 50. Leaning out to balance, Steve thought I was passing my bottles to him and took the leash which would have been helpful indeed if it had not been both a surprise and very heavy with two full 80s of nitrox on it. He and I rapidly parted company – him down and me up – although within acceptable levels. David said after it looked like I’d said to myself ‘You want to breath my gas - you can carry the damn bottles then’ but we quickly settled back down and relaxed.

Al then had to manage a switch to the OC reg on his 50 bottle, clean up the cheater, juggle bottles, plug in 02 and get back onto the RB. Meanwhile I managed the switch to O2 for Steve and myself.

My mask then disappeared, quickly followed by my backup which was taken from my hands with a quick slap as if to say ‘no, that’s just too easy’. We stabilised as a team before I found another being pressed into my hands by Al whilst Steve gave me the all important feedback through touch contact.
And then the surface. We didn’t need to be told we had done well in water that dive. Each hint, comment and criticism that David had given us had been taken on board, acted upon and our performance had improved accordingly.

‘Good dive’ may not be a lot of praise but it was hard won and each of us felt that we had given a good account of ourselves. The final decision as to whether we should be set free with the units was to be David’s but we all agreed that we felt we could have done no more.

Two final dives beckoned – both of which are done to assist in that intuitive development and build confidence in the unit. First we were to try to flood it. We dropped down popped the loop out of our mouths in the open position and sat there. We were encouraged to wave it around a bit, jiggle it and see if we could get as much water in it as possible and then go back on to the loop – in OC mode if we chose before switching to RB. The length of the test was personal comfort and I decided to give it a really good go.

The unit is designed to route water away from the scrubber material and after three minutes or so waving an open loop around I switched back on to it cautiously. Nothing – a bit of gurgling but not much else and no cocktail of nasty stuff. We exited the water and examined the scrubbers. Again, not much. Mine was very slightly damp in the top centimetre but completely dry below with no clumping of absorbent. I understand this is pretty unique to RB80s and clones, and helpful for building confidence in the unit.

As the scrubbers were now empty, we would rebuild our kit and get back into the water with no scrubber material in place to see what a CO2 hit felt like. I am aware that there is some question as to the validity of this test as hits can take different forms, but it was useful to sit there for a couple of minutes, feeling the body try to stretch gradually for breath, in controlled circumstances where someone was looking out for us. Stopping the test was up to each of us, when we felt we had enough we switched to OC and David hauled us out of the water. I felt OK – until I climbed the stairs up the kit area a few minutes later!

Back to EE for debriefs, we were told individually that we had fully passed the course.



Team photo – Steve, David, Alastair and me.

It felt good, it felt earned, it felt daunting as well. MOD 1 – 3 in four days diving is an original concept in rebreather training but GUE’s prerequisites mean that each of us hit the ground running at the start of the course and because all the deco, gas switching process, dive planning etc was all covered in previous classes this class is just about how to apply the RB. David ensured that the pace continued throughout the week! A road map of how to get used to the units and build up to currents diving levels as well as beyond was discussed and agreed with each student.

It was a hell of a journey – and I sit here now not quite believing I did it.

Reflections?

Only when you get through the highest level of GUE training do you get the complete picture of our holistic system.

Clipping off and on one handed – important when you need to use the other hand for other things like donation of gas.

We breath from the right post so that it cannot easily be rolled off, the RB is configured the same way so valve drills are identical to those in OC, turn off the post and breath down.

Never foul the longhose with anything, get used to checking that it is clear as whilst a light cord can be untucked if you forget, a RB feed hose is a pain to reroute and would lead to increasing stress if it fouled a gas donation.

Signals, communication, team positioning under failure, gas switching procedures, deco, all is the same as before. Fundamental buoyancy control and trim greatly aid in water comfort and help build capacity to deal with new equipment and complex failures.

Good reach in drysuits for valve drills. I’m not talking merely about the flexibility that each of us has but a good technique for reaching, with flat or slightly head down trim to assist reaching valves which feel four feet apart.

I write this not to encourage you to undergo RB training. But to open eyes to the importance of the little things, how building that stable platform of fundamental skills can benefit our diving at every level. It’s certainly served me well this week.

The unit itself? Well it’s OK. It’s a tool which I can already see has immense benefits but like most things in life benefits also come with costs and I don’t underestimate them. I had a couple of moments when the Redneck from hell wasn’t raining fire and brimstone around my head when I even quite liked the unit, but then again this was a GUE training course so those moments were very short lived. I look forward to a few more but the day after the course was over I took a scooter, a set of doubles, a stage and some O2 and hit the water in Ginnie. Ah bliss!

Hope you enjoyed the read.

[ukdivver]

Good on you

[aquaholic]

Well done, Clare. Sounds like a hard week's work.

Rather you than me, but I'd sure like to pick your brain on a few bits of the RB80 set up later

CU when you get back.

[wreckweasel]

Remember that discussion? "Trust me, you'll know that breathing in doesnt help, but you'll still it when you're dropping"

Congrats. Will be interesting to hear your shipping costs.....

[Kent Tooling]

Well done Clair

I am glad you enjoyed the course cu when you get back

John

[malcolm smith]

Oh boy, that's a whole lot of equipment you've gone through over the last few years!

Give it another 2 yrs, and I bet you will be back to a single cylinder looking for nudibranches :-)

Well done.

Cheers, Malcolm.

[big_si]

Excellent write up and quite an experience!

Congratulations!

I'll be interested to hear how you start to introduce it to your regular diving now... Nice one!

[IanDennis]

Well done Clare (and Al)

[frosty the snowman]

Well done Clare and an excellent report too. Welcome to the no bubble club!

Now you just need some modern flippers and a proper reel...

[MartyC]

Well done to you all, I think you're gonna need a bigger truck!