Advanced Nitrox and Decompression Procedures

Can you ever learn enough about diving? I don’t think so, so I decided to take a move to the dark side – the era of long hoses and dressed all in black – and something to do with a Blue “H”. What was I letting myself in for?

After my divemaster training I thought maybe that other stuff looked fun, and besides is it not the duty of a divemaster to learn as much as possible about all kinds of diving. So I attached a long hose to my regs, a couple of clips here and there and signed up for a TDI Advanced Nitrox and Decompression Procedures Course with Jamie Obern from TechdiveNZ. Oh, and then spent a lovely 2 hours in Dive & Ski HQ with Claire buying new gear….:)

On Easter Monday I set off at 0600 on a drive north. I was particularly excited knowing my final destination having already visited Northland Dive on “Road Trip North” with Claire and Geoff. Ten and half hours later I arrived at the now familiar cow shed to be greeted by Shane and Julia, who was already cooking a delicious dinner – one of the many benefits of diving with Northland dive. Jamie was not far behind with 4 lots of paper work to fill in. We had added PADI Tech Rec 40 and 45 to our week of study as well. My fellow students Brendon and Simon arrived about an hour or so later and we were straight into the first of 3 long theory sessions. I had read the 3 books prior to the course and my divemaster study had helped, but this really bought it home to me. I could now start to understand first hand what all that physics and physiology was all about.

Days one and two involved skills and drills, and drills and drills and drills. All conducted in neutral buoyancy just a meter from the bottom in only 8 meters of water. We learnt about valve failures, stage bottles, S drills, V Drills, trim, trim and a bit more trim (although apparently less trim than GUE Fundamentals!!). Dive one – 63 mins, dive two – 67 mins, dive three – 79 mins and dive four – 58 mins. By the end of the two days we almost had the hang of it and it was time for the open water.

Day three we set off to dive the Canterbury wreck (another good reason for Northland dive as an excellent learning centre), I was a bit nervous to be honest, I rolled back off the boat, stage bottle attached and moved to the front of the boat for our decent, 6m down and a pod of dolphins just happened to turn up to check us out (No. 3 good reason for Northland Dive). The water was blue and the wreck looked fantastic, but to be honest we did not have much time to see the wreck as the failures (simulated by Jamie “the shark” Obern) started. I think by the end of the dive what could go wrong had gone wrong, but we successfully resolved all the issues and managed a safe simulated decompression dive.

Dive six – could any more go wrong? Yes! By the time we surfaced after simulating 15 mins of deco, both my posts on my twins had failed and so had my stage bottle. I had to share deco gas with Brendon and Simon, who only had one post working on his twins…….oh my! But again we surfaced and had managed everything – this gave us great confidence, although we were becoming very wary of “the shark” and what he could do to us. Lost stage bottles, tangled SMB line, and dreaded failures – would there ever be a normal dive again?

The final day was graduation day, two planned deco dives with accelerated decompression. The first to 40 metres for 25 minutes, with 20 minutes of decompression and the second, back on Canterbury, 36 metres for 7 minutes, 32 for 7 minutes and 30 minutes around the superstructure for 20 minutes before another 20 minutes of decompression. Both dives were great, although the effects of narcosis did make the first one very interesting. On the second dive of the day and the last one of the course, I was conducting a 14 minute stop at 6m, I could look up and see the surface – this really brought home to me what a virtual ceiling is, I could surface in a minute but this would lead to decompressions illness, serious injury or death!! All those drill we had gone through now made sense to me, we were able to cope with everything thrown at us and were really doing technical dives – but there is still so much to learn.

Big thanks to Brendon who organised the course, Julia for cooking such lovely meals and Shane “the wookie” for letting me win at least one game of cards (let the wookie win R2). And last but by no means least, thanks to Jamie for making the course such fun and so challenging. I had a great time and can’t wait for the next one.

Stuart Brown

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