Learning to use NITROX by Dermot Kelly (May 2002)

The night before, I decided to look… wow I thought what have I let myself in for. I started perusing through the student copy of basic Nitrox, the book was well set out and a good read, not too technical but demanded a fair level of concentration. The second book Advanced Nitrox looked into the technical side of the business, using Nitrox as a decompression gas etc and formula. Not to be too daunted by the math I went to bed and had a good night's sleep.

The next day was bright but overcast, we all planned to meet in the university grounds at 09.00 hrs. Luckily it wasn't raining as Jon had brought a large amount of equipment including cylinders etc for the show and tell part of the course.

Once in the classroom we all sat down and John introduced himself and the rest of the training team. John is the Yorkshire regional BSAC training coach and his team for the Nitrox course were Chris and Liz Storey and Ray McKee. The introduction to the course was extremely professional including the presentational devices and slide show. John and his team were well read in the subject and answered all those awkward questions we all like to throw in. Throughout the day all matters regarding the use of Nitrox were discussed.

I quickly became aware of the physiological benefits of using Nitrox. In my opinion Nitrox will vastly reduce the effects of getting a bend than by using Air.

I was shown, and later convinced that Nitrox is the way forward for me, now that I am on the slippery slope to my dotage (40). 

The slide show and the lectures were very informative and useful when trying to calculate CNS gas loading (Central nerve system) or UPTD unit of pulmonary tissue dosage. I was not looking forward to the math or calculations of the course but with the correct tables everything went well.

With all the theory safely onboard we then had a show & tell, in the classroom we all played with the toys John & Ray had supplied for the course, gas analysers, pony cylinders and dedicated Nitrox regulators. The gas analyser is a technical piece of kit used to check the % of O2 in the mix. Ray had managed to bring along 4 different types of gas analyser varying in design and of course price. It was interesting to see which type repeatedly recorded the same results each time.

Once the demonstration had finished John and the team re visited items of importance on the days teaching before giving us a little test, the usual multi-choice answer format. 

The day was now over at 18:15 I arrived home buzzing with Nitrox theory!

Day 2. Capenwray. The trip to Capenwray was uneventful approx 145 miles to the newcomer, on arrival I had to register with the clubhouse, as I was a virgin to the delight's of Capenwray a £2.00 membership, and a fiver to dive. The new clubhouse was very appealing with all new facilities, nice view of the water and pleasant wild life to see. 

After the check in, back to the car park to get kitted up. Ray & John had brought lots of kit for the trainees to try out. The kit configuration was indeed a part of the course which is important as using an extra cylinder either slide slung or configured with your original kit would alter your attitude in water & buoyancy. We all took notice of numerous ways of mounting the extra kit, it was great fun!

John presented an overall pre dive brief and the trainees were split into groups with Liz & Chris Storey, Ray McKee and John for individual SEEDS brief & buddy check.

I was teamed with Ray and a trainee called Chris from Sheffield BSAC branch. We entered the water around 10.30 and finned out to the helicopter, descended to the wreck about 15m. The viz was approx 3 metres. At the wreck I followed Ray and Chris my buddy, the plan was to deploy a delayed surface marker buoy, ascend to a deco stop and switch regulators & gas for a simulated deco stop.

After the first dive we had a de brief and a discussion of the finer points and technique of using the equipment. We had a spot of lunch and a rest to give ourselves a decent surface interval. I had a look around the facility and found the shop well stocked with the usual dive needs. The café area is spacious and I'm told the food is good.

Dive 2. After a surface interval of 2 and a half hours Ray, Chris and I kitted up for our second dive. Again we entered the water by the shore and swam to the Oilrig platform. We all descended to the platform, this time the viz was at best 1,5m. This was a good time to use navigational skills & compass. The second part of the dive we had to release a delayed surface marker buoy mid water while keeping our buoyancy. I was confident of this drill but every deployment of a DSMB is different! "Oh Bugger" 

We all managed to master the drill even if when you release your smb you may be a little close to your buddy. Although it never happened to us there can be a lot of untangling of lines to do at the surface.

Back on shore Ray conducted a dive debrief and we were pleased with the overall success of the day. John and the training team held a debrief for all trainees in the café and then proceeded to release our test results. The pass mark was high but the level of attention and hard work had proven to be excellent as all the students passed. This we can all assume is due to the dedication and hard work of the training team of John Dunwell. I would like to thank Chris, Liz & Ray for giving up their weekend to train my fellow trainees and myself. A truly enjoyable course jam-packed with 110% usable information what every diver needs to know.

Dermot Kelly