Module 2 & 3 Tech rebreather course completed

David Jerram tells us all about his module 2 & 3 technical rebreather course with Rich Stevenson in Lanzarote.

I've been diving on the Inspiration rebreather for a while now, and recently found myself wanting to be able to take it a little deeper than the restrictive 40m limit that I self imposed after my module 1 course in February 2007. In the past I have been trimix diving to around 70m on open circuit scuba, and I really missed the thrill and adventure of deep wreck dives in the UK.

In theory, putting trimix into the rebreather is easy. It seems like what the Inspiration Vision was designed for - and diving on rebreathers is ideal for deeper and longer durations because of the efficient use of gasses. However, there are limiting factors, including the amount of 'bailout' gas that the diver or team of divers can reasonably carry. In addition - just like open circuit trimix - dive planning becomes a lot more complicated the deeper you go.

David Jerram on a 6m deco stop after a 60m dive

So I decided to research the IANTD module 2 rebreather course and to find for a suitable instructor. My search lead me to Rich Stevenson of Deep Blue Tech in Devon. Rich is known to me because I did my open circuit trimix qualification with Deep Blue in 2001. Also, Rich is well known from his expedition dives on both the Britannic and Carpathia amongst other exploits. Rich was very helpful when I called, and gave me the choice of either doing the course in Plymouth in February, the NDC quarry at Chepstow - or joining in a forthcoming course in Lanzarote. Now, given that I am not good in rough weather on boats - and that the NDC will be freezing the choice was a 'no brainer'. I booked a flight to Lanzarote immediately and flew out on 1st November.

I flew 'First Choice' who kindly gave me an extra 10 kilos of luggage allowance for sports equipment (call a week ahead to confirm this if you want to fly with them) - and the Inspiration in its freight box wasn't even weighed as it was too big for the normal baggage path at Gatwick's check in. So, thankfully no excess baggage for me :-)

The course was held at The Dive Shop in Puerto del Carmen, Lanzarote, which is owned and run by the affable Simon. The dive centre is really well equipped with all the usual scuba gear for hire along with Inspiration, Megladon and soon to be Sentinel and Cis Lunar rebreathers. There is a well appointed compressor room with Helium, Nitrox and a gas booster. Simon runs a very tidy operation and keeps everything spick and span (a throw back to his days in the army) - although his demeanour is incredibly relaxed and welcoming.

Our accommodation was a superb apartment just 20 minutes drive away in the quiet part of Costa Teguise, and I was staying with Rowena and Luca - two OC trimix instructors from Rome who were also on the course with their Megladon rebreathers. My lack of Italian was capably matched by Luca's lack of English - but thankfully Rowena was an excellent translator and we got on really well for the week.

Collecting stage bottles before a dive

Day one saw us in the Dive Centre assembling our units and prepping them for an afternoon of weight checks, buoyancy skills and stage cylinder drills. We chatted through the drills we would be expected to perform in the week which included:

'S'-drills on every dive to check stages/bailouts were working and checking units for leaks.

Regular 'surprise' bail-outs at unexpected moments to either a trimix stage or a nitrox stage depending on depth.

Stage bottle removal and replacement while swimming mid water.

Stress tests involving swimming a line without a mask, rebreather mouthpiece or regulator.

Gas sharing exercises

Bailouts at depth with ascents within a planned schedule.

Solenoid failure drills (both stuck open and closed).

Loss of Oxygen drills (semi closed rebreather swimming).

Loss of Diluent drills.

Management of stages between team members.

Boom scenario management (failure of either high pressure hoses on the rebreather).

And much more...

All drills were conducted mid water, and the use of two stage bottles on each dive was of course mandatory. Managing stages appeared to be more complicated for Rowena and Luca who mounted their bottles all on the left side DIR style. I normally put a deep stage on the left and a nitrox stage on my right. However, the skills were refined over the week and by the fourth dive everyone was pretty proficient with stages.

We conducted dives to 60m and spent a good deal of time planning the decompression and bailout requirements. The Vision's on board decompression made dives easier - but our team planning was done on GAP using RGBM which gave us longer shallow stops and deeper first stops.

The dives all involved a short (10 to 15 minute) swim out from a bay. The further we swam the water became rapidly deeper (and Lanzarote can give you 200m plus if you venture far enough). It was very relaxing not to have to worry about tides or boats at all for the week.

Checking PO2 during a swim back to the shore for a well earned light lunch...

The marine life in Lanzarote was a bonus. I had not expected to see too much, but was pleasantly surprised to see Angel Sharks, Rays and Octopus on most dives. Our final dive was the most memorable, with a very large Manta pursuing us up from 45m on our deco stops. Rich turned around in time to see the Manta looming like a huge vampire just behind me and Simon. He said it looked like it was going to eat us both (which would have been a challenge considering our combined weight and size). We extended our stops by a couple of minutes so we could spend a little time watching the Manta putting on a fabulous display for us.

Luca, Rowena and Rich Stevenson in Lanzarote

By the end of the week we had all completed Module 2, and Rich was happy to take us all into Module 3 which would see us in 80m. The planning and dive management were handled with great care, and both dives on the final two days went very well indeed.

We all three succeeded - and I felt like I had learned a great deal about the planning and management of technical rebreather diving. I can't wait to put it all in place on some south coast dives in 2008. What I do know more than anything is that it takes a lot of training and experience to become safe at depths below 40m. I also learned that you need to be fit and in shape if you are planning trimix dives to 80m. I have my work cut out for me this winter.

Want to know more? Contact David Jerram for more information on rebreathers and how to get involved with mixed gas diving.

Email: do@cpanet.co.uk