Mixing it with PSA
With the UKs latest trimix course to evaluate, our training correspondent Chris Boardman headed off to Dorothea Quarry in the company of Mark Andrews. But first some deep-air practice was required...

AS WE LEVELLED OFF AT 66M, I USED MY DRY-GLOVED LEFT HAND to feel around among the array of hoses, regulators and pressure gauges criss-crossing my chest for the suit inflator button. I added a long blast of argon.
     The water clarity was superb but it was still almost dark. The bottom, some 20m below, was impossible to see.
     Using the torch on my mask, I checked my gauges for the second time in two minutes and looked back up the dramatic cliffs in the dim light to see a bizarre sight. It was a tree, standing upright on what 40 years ago had been a headland, but was now 40m under water in Dorothea Quarry, North Wales.
     When I reviewed PADIs Tec Deep Diver programme, I expected a PADI trimix course to follow swiftly. Sadly, there is still no sign of this option and it could be some way off, if it ever materialises.
     Meanwhile, a trimix training course ripe for me to review appeared from a fresh source - the Professional Scuba Association, founded some 15 years ago in the USA by Hal Watts.
     The PSA, now approved to teach technical diving in the UK, offers more than 12 courses, from Deep Air Level I (to 30m) to Expert Trimix (94m), with Cavern, Cave and Wreck specialities in between. All these programmes have been set up by Mark Andrews, the PSAs UK director.
     No problem, said Mark, when I suggested I review the Basic Trimix course. We can do it in Dorry!
     At the time, sitting at my desk in my warm office, this seemed a great idea. What a contrast it would be to the TDI and PADI courses I had undergone in the inviting waters of the Red Sea! The PSA also claims to be the only agency with a 100% safety record during training. I was happy about this and keen for it to maintain this status.
     As I had not come through the full PSA program, I agreed to start with the Deep Air III course (46m) so that Mark could check me out. If all went well, we would do Basic Trimix (66m) the following week.
     Mark Andrews has logged more than 5000 dives since 1993. He got into tec diving in 1997 and became a controversial figure when he set the world depth record for an air dive at more than 156m, an experience he was lucky to survive.
     Controversial he might be, but he has been there, done it and survived, so he has a rare insight into the subject he is teaching. Insistent that no one should attempt the air record again, he has now set his sights on John Bennetts new 1000ft trimix mark, with a dive so deep that he intends to use a submersible to verify the depth!
     Late last year two manuals dropped through my door. They were the now familiar format used by most tec agencies apart from PADI/DSAT: home-printed, no frills, mostly black and white, minimal illustrations. I suppose most people appreciate this if it cuts the cost of the course.
     Presentation aside, I was disappointed by the content. In trying to cover all four Deep Air courses taught in the UK with one manual, this was a broad overview of technical diving rather than a reference work. The knowledge reviews didnt aid learning either.
     Having said that, such criticism could be levelled at most tec-diving agencies, and Mark Andrews is at least encouraging feedback on his materials and courses. In fact my manual had been updated even before I started the course, with a further edition in the works.
     The Trimix manual was better. There were no illustrations to support the text but it had a specific course overview, a detailed list of equipment requirements and lots of mathematical information necessary for planning dives.
     The statement being out of air is not an option for a PSA diver crops up often, so both manuals incorporate a dive-planning sheet to help make gas-planning more systematic. This was simple to use and understand.
     As it turned out, the format for neither course really required a manual.

DAY 1: Deep Air Theory
Mark and his assistant Kevin turned up at my office on the Wirral after a gruelling six-hour drive. Theyre used to doing a lot of driving because they need exceptionally deep water for this type of training. PSA UK has looked into moving its operation to this part of the country but is in limbo because of the land disputes surrounding Dorothea Quarry.
     We would spend nearly 14 hours over the next two days covering theory for both the Deep Air II and Trimix courses, before heading to Dorothea for the dives.
     Mark Andrews is a down-to-earth character, quietly spoken but passionate about what he does. With the PSA, he says, you pay for the training and time spent with an expert, not for the qualification, which has to be earned.
     A diver who fails to meet the required standards will be referred, without a certification card or refund, for further training. This is a responsible stance, but could be difficult to maintain in the real world.
     He also explained the thinking behind Deep Air courses: There are people out there who are going to do it whether its sensible or not, so should they choose to accept the increased risks involved, we can instruct them in good diving habits to minimise the hazards.
     The lessons took the form of a workshop, with opinions flowing back and forth as Mark worked through the instructor manual. There were no slides or flip charts.
     I tried to keep an open mind as I grilled him about diving habits and equipment configuration. He was able to produce solid rationales for his controversial opinions and I admit that he even won me over on a few issues.
     I enjoyed this interactive format. On almost every topic I was asked first what I considered to be the right way, forcing me to examine my own views and habits. If these conflicted with Marks, we would discuss the thinking behind each methodology.
     Mark believes that when using air at depth it is nitrogen narcosis that gets you into trouble first, and that it is this that often leads to oxygen toxicity problems. Considering his background, I was willing to go with him on this one.

Day 2: Trimix Theory
Over six hours I heard little that was new to me, but then anyone considering a mixed-gas course should already be well-versed in tec procedures.
     Most of our time was spent discussing helium and its effects, dive techniques to allow for these limitations and gas-planning on paper, using calculator and equations as well as software programs to work out the best mixes for our upcoming dives.
     Helium has virtually no narcotic effect, so by using it to replace a lot of nitrogen, I could have the same narcosis level at 70m as I would have at, say, 30m on air. The inevitable downside is that, being so light, helium diffuses into the tissues far more quickly than nitrogen and also comes out faster, so to prevent a helium bend decompression stops start deeper and ascent speed is reduced by at least 30%.
     For our 66m dives, we decided on a heliair mixture. This is blended by adding pure helium to a cylinder and then topping with air. Our final mix was to be 12% oxygen, 43% helium and the remainder nitrogen, expressed as 12/43.
     As air contains 21% oxygen and this mix would contain only 12%, it is referred to as an hypoxic mix and is not safe to be breathed until about 4m under the water. For decompression, we calculated that two 7 litre cylinders containing 40% O2 and 80% O2 would suffice for the scheduled mix dives and training dives on day one.
     It was a fascinating session. I found each day that if I was sufficiently well versed in a subject, Mark would not labour the point but move on.
     Day 3: Air Dives
     No specific skills were to be tested but I admit that I was feeling nervous about that first dive to 46m in cold, dark water on air.
     I would lead the dive but I knew that Mark would be trying to lead me astray by behaving like a poor dive buddy to demonstrate the effect of narcosis on a divers judgment. He had managed it before with many more experienced divers than me.
     My apprehension had grown the night before when, assembling my kit, I found a leak in my carefully prepared twin-set. I had been forced to cobble something unfamiliar together and to take a slung cylinder as an independent air source.
     There were grey skies over Dorothea. It was 6ÂC on the surface and 5Â in the water.
     The dive plan was as follows: Pre-entry equipment checks; bubble check on entry; swim to descent line; record gas pressure before descent (once cylinder has cooled); descend at about 15m per minute; give get neutral signal (to start decelerating); give level-off signal at predetermined depth; give 4 minutes gone signal; give level-off signal at bottom depth; record gas pressure of both divers (having a potentially narked buddy tell you his cylinder pressure is not good enough, each diver verifies his own and his partners air supply); check both divers air every two minutes for remaining bottom time; at any point show a pre-determined compass heading; remember an object indicated by Mark; give 1 minute to ascent signal; record gas pressure and prepare for ascent; initiate ascent at maximum 10mpm; indicate level-off at stop depth and hold it; give surface signal.
     Dive 1 was a little ragged but I went no deeper or longer than planned. This was not because of the absence of narcosis, of which I had plenty from 35m down, but because the plan was simple and there were no big surprises.
     However, these tasks had taken all my mental ability to achieve, which, of course, was the intended lesson.
     On Dive 2 the familiarity of the routine reduced the narcosis drastically, though had things gone pear-shaped Im sure it would have returned with a vengeance.
     I got more from the day than I had expected, learning about the more subtle dangers of narcosis, what I could expect from myself under these circumstances and how to plan accordingly.

Day 4: Trimix Skills
A week later we were back for the Trimix course. I was joined by regular dive buddy Paul Chapman, the PADI Master Scuba Diver trainer who taught me to dive. As he had missed the Trimix theory day, Mark had kindly agreed to go over it with him long into the previous night.
     That morning the weather was as bad as it could be, with dark clouds, wind and driving rain. With little in the way of shelter, we spent the day wet. Photographer Craig Nelson was having kittens over the low light levels in the car park, let alone at 40m, but, confident of his abilities, I got on with my preparations. Both dives would be made using air but simulating a trimix dive, with all decompression cylinders carried and ascent rates reduced to 10mpm.
     The plan for Dive 1 was: Pre-dive equipment check; entry and bubble check; 15mpm descent to 40m (switching to back gas from 4m); ascend back to 30m where one diver (to be decided on by Mark at depth) would simulate being out of air; ascend at controlled rate to 9m with OOA diver on the others long hose; switch to 80% deco mix; stow hoses and launch DSMB while hovering; give DSMBs to Marks assistant Pitre and drop onto 10m ledge for stage-cylinder removal and replacement, with eyes both open and closed; repeat this manoeuvre while hovering at 6m; surface.
     Again everything went to plan, again a little raggedly. I was about to indicate for us to surface when I turned to see Mark swimming towards me giving the OOA signal while spitting his reg out. As I gave him my long-hose regulator, he decided to simulate lost buoyancy too, by dumping all the air from his wing! I just managed to grab him as we started dropping fast, and hit my wing inflator button.
     I was using a Diverite Rec wing, which has 51lb of lift, but although Mark was not even carrying stage cylinders, this amazingly wasnt enough. I was forced to use my drysuit to obtain additional lift.
     I am close to neutral with near-empty cylinders and only the air in my suit, so all that lift was needed for Mark, who was carrying a lot of dumpable weight just for the exercise. Had I been wearing a wetsuit, drastic measures would have been required.
     Dive 2 followed a similar plan, but this time the stage removal/replacement exercise was done at 30m while hovering over an 85m drop in the dark. DSMBs would then be deployed from 20m.
     After each dive Mark walked us through it in a lengthy debrief, encouraging self-analysis before giving his own opinion.
     This was the point at which either more air dives would be scheduled or the course would end if he considered our skills insufficient. I believe he would do it, too. As it turned out, we all felt happy to continue, so it was back to the B&B in Betws-y-coed for Paul to study some more theory while I started drawing up tables for the real trimix dives.

Day 5: Trimix Dives
This was the day that I have least on which to report. Both dives were blissfully uneventful and, thanks to the clear head provided by the helium, enjoyable. No training was incorporated into the dives, as the required skills had to be in place by this time.
     Paul and I had adopted some of Marks tips and they worked well.
     For instance, by moving our pressure gauges from the left hip D-ring to a position across our chests, we found we could check our own and each others pressures at a glance, which encouraged more regular gas checks.
     Again, to deploy a DSMB in cold water without having to push the purge button, I usually hold the bag over my regulator exhaust and exhale to fill the sausage. However, you do tend to float up as the bag fills. Mark suggests using air from the wing via the low-pressure inflator hose. Buoyancy is relatively unaffected, as the air is simply transferred, and you can release the bag in your own good time, replacing the air in the wing to remain neutral. Easy!
     A third top tip involved LED lights. Mark used three small ones on his mask to produce the perfect amount of light for reading gauges without destroying night vision or blinding your buddy, as my mask torch tends to do.

The PSAs style is unlike that of other technical courses I have experienced. The association will train divers from other agencies, but because its programmes are sequential, it suggests that best value is gained by starting from Advanced Open Water/Sport Diver level. If its informal approach appeals, perhaps this is the route for you.
     Most agencies state a minimum and maximum depth for each course, but the PSA teaches exactly to the depth stated in the course title.
     The manuals need attention, and classrooms were of necessity makeshift, but I enjoyed working with people who really know their stuff.
     I might not have agreed with Mark on everything but I respected the reasoning behind his arguments and liked the way he encouraged students to learn for themselves. Paul and I both felt we got what we needed from the course.
     The training is not cheap (I would worry if it was). The extra equipment needed is immense (and, because you need to be familiar with it, you wont want to hire it). Neither is helium cheap, and as you cant inflate your drysuit with it (it is a poor insulator) you need a separate cylinder for suit inflation.
     This might explain why so many divers convince themselves that they can do deep dives on air and then get into trouble with narcosis.
     I am convinced that this is behind many incidents at Dorothea, placing the future of this beautiful and unique site in jeopardy. Based on what I learnt on the PSA course, if you plan to dive to 65m on air in the UK, Im afraid youre asking for it.

Mark Andrews (left) conducts a pre-dive briefing in the relentless rain
preparing to dive
Chris Boardman does some visualising
making a gas switch
Making a stop
gas analysis
setting up early on Day 2
Paul Chapman ready to go
The trainees practise skills on the bottom
Divernet Divernet
The classroom facilities were somewhat rudimentary
stage removal and replacement while hovering in the dark at 30m
Dorothea at its best ... the divers are debriefed in the sun

From Advanced Open Water/Sport Diver level:
Deep Air I £250
Deep Air II£275
Deep Air III £300
Deep Air IV £375
Basic Nitrox £250
Advanced Nitrox      £275
Techtrox £400
Basic Trimix £475

Twin 12 litre cylinders, with bands and manifolds£395
Two 7 litre stage cylinders, O2 clean and rigged £275
Two stage regulators with short-hose SPG £400
Two deepwater regulators, one with long hose £450
Argon cylinder with fixing kit, first stage, SPG and hose £275
Wing able to lift two divers £315
Backplate and harness £90
Two lights (minimum), one hands-free £300
P-Valve kit£60
Semi-dry hood £20
Dry-gloves £60
Back-up computer, gauge capable£200
Cutting devices £50
Total £3540*
* Based on shop prices, not RRP. 10% discount may be available on bulk orders

Helium mix 12/43 24 litre at 240 bar£48
Argon 2 litre at 200 bar £5
Nitrox 40% 7 litre at 230 bar£6
Nitrox 80% 7 litre 230 bar£6
TOTAL for two one-hour 66m dives £65

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