IF THERE’S BUBBLES,IT’S LEAKING!!
(by Clive Bowen)
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For a few years now, I’ve been looking fairly seriously at rebreathers. I’ve been doing a lot of background research on various types and getting more and more drawn into taking the plunge and buying one!! Over the last few years, I’ve also been doing rebreather try-dives-firstly at the Dive Shows, then in the pool and finally at Stoney with Arnold. I’d got my preferred choice of units down to 2 by the end of last year-the Ambient Pressure Diving’s Inspiration with the new Vision electronics and Innerspace Corporation’s Megalodon. Both are electronic closed circuit rebreathers-and both do the same job-so which one gets the nod?
Well, the Inspiration is probably the most well-known rebreather on the market today-for one its sold more than 6,000 units worldwide and secondly, it’s very distinguishable by its bright yellow box. For short, its known as a YBOD-yellow box of debt! The Megalodon on the other hand, has sold far fewer units and is relatively unknown outside the rebreather world. This might now change, as it’s the unit used by the divers in the film-“The Cave”. When I first saw the Meg, about 2 years ago, I was very impressed by the quality of the workmanship and materials of the unit-something which the mass-production of the Inspiration can’t match. However, there was a problem in that there were no plans to have the unit CE marked-which would have had an effect should I ever have decided to teach on it and would also have an effect on how it would fit within BSAC diving. Also, based in the States, and without European representation with regards parts and servicing, I didn’t feel it was the right unit for me to buy-even though I liked it very much.
So, the focus went on the Inspiration and at this year’s London Dive Show, I booked an Inspiration course with Penny Glover in November of this year-having ordered my unit for October delivery. Big excitement and big commitment!! That should have been that, but now that I’d ordered the unit I began to feed my appetite for rebreather information even more-and while going through some web pages, I saw a link to Custom Divers’ website and their link to the Meg. I had a look at their site and saw that they had become the European sales, parts and service centre. They were also in the process of getting the Meg CE marked. This changed things. I rang Alex at CD, who gave me more info and invited me down to their offices to see the “nearly finished” homologation unit for CE marking. I didn’t need a second invite-and off I went. My feelings for the unit were as strong as previously-but with CD’s backup, now there was no competition-and I placed an order for the Meg for delivery about December this year.
OK. That’s the adrenaline rush over-let’s put this into perspective. I’ve now got 2 rebreathers on order-what do I do now? Do I keep both orders and dive the Inspiration until the Meg arrives? Then what do I do with the Inspiration? I wonder if Helen wants to learn to dive a rebreather? In the end, there was only one answer and that was to give up my option on the Inspiration (they don’t take a deposit when you order a unit, as if you don’t want it, it gets passed down to the next person in their queue-which is currently 12 months wait).
That’s it. I’ve got the unit I really want on order-but maybe I should dive with it and see if I get on with it! After speaking to Alex at CD, he puts me in touch with Chris Hutchison an IANTD Instructor on the Meg to arrange some training. We fix a date of September 25th-October 9th to do the Meg user course and step up to the Meg Normoxic Trimix course-which I’m able to do as I’m already qualified to this level on open-circuit scuba. Oh, and we’ll be doing the course out in Sharm in Egypt. But it’s only the summer and there’s months to go before then and I’m not working-so I do the BSAC Inspiration Mod 1 course with Dave Simmons at Gildie and at Stoney-a really enjoyable course and worthwhile doing because of what’s coming ahead.
After talking over things with Chris over the previous weeks, it’s the 25th and we’re at Gatwick airport. I’m flying out for 2 weeks, and Helen’s coming out to meet me for the second week. I meet Chris at the terminal, pick up the big green box with the Meg in and head off to check-in. It’s really busy and it looks like everyone’s getting clobbered for excess baggage-well I haven’t got a hope of getting away with it and I finally manage to negotiate only 16kgs of excess baggage! The flight’s great, get to the hotel which is only 10 minutes walk from Tekstreme at Emperor Divers, where we’re basing ourselves and get prepared for the next morning.
After getting the dive
centre’s bus, I meet up with Chris and the other 2 students on the course-Al
from Australia and Zy his girlfriend from Hereford. We start the course with a
leisurely coffee and then get to work. Today we’re planning to assemble the
Meg ready for a shore dive this afternoon. We go through a 45 point check
sheet-something we do every time we assemble the Meg-lest we forget something
vital. By lunchtime, things don’t look so good as Al’s unit has a faulty
oxygen injection solenoid and Chris has to go to Radio Shack to get a new one
and solder into place-so we just build the units ready for diving tomorrow. By
5.30pm we’re finished then it’s back to Chris’s room to do 2 hours of
lectures-something we did every night! Tuesday
morning arrives-excitement and apprehension!! We’re on the boat Sonia-Chris
the Instructor, Al, Zy, me and Mikael from Tekstreme who’s doing a Meg
crossover course and who’ll be our dive guide on some of the sites as well.
We’ve plenty of room as sometimes they have up to 20 divers on the size boat
we’re using-but we’re technical divers so we need the space for all our
gear!!
On the way out to the dive
site-White Knights-we’ve had a dive briefing from Mikael and from Chris. This
first dive is to get used to the Meg, sort our buoyancy out and to do some basic
skills. Planned dive time is 2 hours with a 20mtr depth limit. Some final checks
on the unit, kit-up and attach the 8ltr cylinder for bail-out, a few minutes
pre-breathe to check that the solenoid’s working and to start the CO2
absorbent chemical reaction, air in the wing and we’re off the back of the
boat. We descend onto the seabed in about 5-6mtrs of water and just wait there a
minute to acclimatise ourselves and to get used to the different breathing
characteristics of the Meg and to check the handsets to check things are working
OK. Once we’re happy we start doing skills such as closing the mouthpiece and
removing and replacing it and going onto open-circuit. We practice our
buoyancy-I’m carrying 4kg on my belt along with 1kg attached to each of the
unit’s 3ltr onboard cylinders for trim and with my 5mm wetsuit, I’m
overweighted and take 2kg off from then on. We practice drills for the onset of
the 3H’s-hypoxia, hyperoxia and hypercapnia all of which can be major problems
on a rebreather. The time flies by and we surface after a dive of 124mins with a
max depth of 16mtrs.What a terrific start and I’m sure now that I’ve made
the right choice.
For the next 9 dives that week, we continually practice various skills for long portions of the dives and have to react to problems set by our Instructor on the dive. We’d be swimming along when he’d thrust a notepad with a problem on it which we had to react to. These could be anything from running out of O2 to a total electronics failure to feeling weird. But the only way to remember skills is to practice and practice and that’s something we did a lot of. Dive times were never shorter than 95mins and were usually around 110-120mins with max depths increasing to 31mtrs by the end of the first week. By the Saturday night, with 2 long dives a day and with a couple of hours lectures, we were glad of a day off on the Sunday. I met Helen at the airport and we had a nice relaxing beer before the start of week 2. Helen came out with us on the boat that week-one of only 2 open circuit divers there-the other being Chris’s partner Christina Campbell-who until very recently was the world’s deepest diving woman from her expeditions on the Brittanic shipwreck-so Helen was lucky with her dive buddy!
This second week would now be the Normoxic Trimix part of the course so we would be diving with trimix as the diluent and not with air as we did during the first week. With the Meg rebreather, the O2 percentage in the onboard diluent mix is determined by a partial pressure of 1.0bar at the maximum depth. On our first dive , we were carrying trimix 15/31-15% O2 giving us a PPO2 of 0.95bar at our planned max depth of 50mtrs and 31% helium to give us an equivalent narcotic depth of approx 33mtrs. We were also carrying a 20/20 mix in our bailout cylinder. Maximum PPO2 of 1.2 allowed in the bailout mix.The first dive was again at White Knights with a dive time of 105 mins and a max depth of 46mtrs. We went down to a wreck of a diving dayboat which caught fire and sank here in the ‘90’s. Again, during this week we did a great deal of skills practice, out of air gas runs, open circuit bailout’s from 48mtrs, multiple stage swaps and so on-again with the emphasis on practice, practice and more practice. We were still doing long dives but not as long as the previous week and we were controlling the amount of O2 uptake due to the possibility of CNS from our prolonged diving. Maximum depth was just over 51mtrs in Jackfish Alley where we saw the biggest moray eel I’ve ever seen. Probably the beat dive was at Thomas Canyon where you swim under an arch at 46mtrs with 2 further arches below you at 54 and 70mtrs-maybe next time.
I’d also had a chance to dive with Helen for parts of the dives and then she’d surface with Mikael the guide. By the time we’d done our last dive on the Saturday, we were tired. We’d done 21 dives with over 35 hours of dive time and an average dive time of 100mins.We’d seen wrecks, loads of fish, turtles, Napoleon wrasse and got to love using the Meg. We’d passed all the practical assessments and done 2 exams in the evenings and passed those as well!! On the Saturday afternoon we chilled out on the boat and got the kit sorted to take back to the dive centre. Once there, the hoses and counterlungs were disinfected before packing away for the journey home the following day. Helen, myself, Al, Zy, Chris and Christina and Polly, their 14month old daughter then went out for a celebration meal on the Saturday night-well, a pizza.
Sunday morning came and we packed for coming home. We arrived back in Gatwick at 11pm and drove home and had a nice lie-in on the Monday as we both weren’t working. Well, it was a terrific 2 weeks-the diving was great, Chris, Al, and Zy were great and the Meg was fantastic. Roll on year-end for mine to come.