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Advanced Trox and Deco - Thoughts and Lessons The summary
If you want to do an easy course that gives you a nitrox cert but doesn’t put you under a great deal of pressure, don’t even think about doing a TDI course with Mark Powell. If you want the cert, but also want to be honestly assessed, assisted, and want your skills and attitude to improve dramatically, you can get hold of him at http://www.dive-tech.co.uk.
The Brief
I wanted to do a deco procedures course, as my dives of between 30 and 40 metres were becoming limited not by volume of gas, but by bottom time. The deco procedures course seemed a logical step. I was already diving nitrox, but liked the concept of using richer mixes to do accelerated deco, or to add a safety cushion into safety and deco stops. The TDI combined advanced Nitrox and deco procedures couse seemed the logical step.
The preparation
I had already made enquiring about doing the course with various instructors, and at various locations. Recommendations from this board, and from referrals pointed me in the direction of instructor Mark Powell, himself a YD member. He offered an intense 2 day course at a good price, and had a course scheduled for this weekend. After paying for the course, materials were delivered promptly, together with all the required legal forms. Mark stayed in touch about the weather, and made the wise decision a couple of days in advance to abort the Portland course, and move it to the NDC in Chepstow. After sorting out my equipment on the Thursday night, I left work at 4pm on Friday and drive to Wales. I found the hotel ok, and met Mark, Nick (doing the advanced Nitrox element of the course, and safety diver Adam. Over a beer we chatted diving, training and the world in general, and had a relatively early night ready for a 9am start Saturday morning. All systems go.
Saturday
The plan was to spend the morning going through the required theory, and then do two dives. There were three of us on the course. Myself, WreckTrekkie, and an instructor Nick, doing just the advanced Nitrox element. We were greeted in the classroom with the words “I make no promises to pass you on this course, and reserve the right to ask you come back and demonstrate any skills I think you need to work on”.
WreckTrekkie and I exchanged a very nervous glance. We then began the theory section of the course. Let’s not piss about, Mark knows his stuff, and communicates it effectively. I am not going to go into the details of the theory, because the most important thing I learned is that Web research and peer chatting is absolutely no substitute for training from someone that knows his subject. Needless to say, questions that I had in the classroom regarding M values, Gradient factors, deco models etc were all explained concisely. The end of the theory section in the morning was to plan the first dive. This was to be essentially a checkout dive, to find out where we all were, and go from there. We would also put in place the basic elements that would be on all dives, planning on a slate, team communication, an smb deployment for all divers. This will now be the case for me on every dive, shallow or not. We made our plan, kitted up and were taken to the water in the back of a land rover that looked as f it might indeed have been rescued at some point or other from the bottom of the lake.
Dive 1 – Dipping our Toes in the incident Pit
This was to be a short dive, but as with all dives on the course, we would be following a plan that included simulated deco stops at 12 metres, 9 metres, and 6 metres. I was VERY nervous about this dive. I was very well aware that I had several hundred dives less than anyone else on the course, and years, if not decade, less experience. Having less than 100 dives, I knew, and informed Mark, that I was doing the course very early, but wanted to do it before I had gained to many bad habits, and put myself or other divers in trouble through lack of knowledge. Thus I was open to the possibilities of having to retake the course. Dive 1 was, well, Mark wanted to find out where we were and he did. He told us he was going to put us into stress and he did. My gas shutdown drill didn’t happen. I had stupidly mucked about with my harness and simply couldn’t reach. Whilst trying, my buoyancy was a farce. My SMB unravelled, and a spare given to me by WreckTrekkie bird nested immediately. At this point I lost cotact with the other students, and went into “cente of universe mode”. I forgot entirely about the plan and became self absorbed.
Now, this was the first time I had been under real stress in the water. Normally, I am pretty cool in the water, or so I thought. Stress, however, is another mater entirely. When things go wrong, it appears the go wrong in groups. Your brain seems to struggle for a while and cope with it all, but in fact I was gradually losing any control at all. I am a Pc techie at heart, and I could feel my own mind going “Warning, you are running low on virtual memory”. As I started getting more and more angry and frustrated, I reached a point where I went “BOOM. Your system has become unstable, please reboot”. I just gave up thinking , and relaxed on the bottom. At this point, I decided that I did not care about all the tasks etc, lets just sort it out one at a time. I can breath, so that’s ok. Can I see my buddies – No. Well, check the plan, and its time to ascend anyway, so let’s follow the plan. The SMB is a nest, so let’ just wind it slowly manually. Concentrate on the deco stops, surface. Ironically, once you just chill and deal with things one at a time, that’s when it comes back together, that’s when you deal with the problems. That fact was probably the single most useful bit of knowledge on the course. When the shit hits the fan, chill out and deal with one thing at a time, don’t try to be the master of all things, because you will mess them all up.
I made the ascent ok, and kept to the planned simulated deco stops. I surfaced with Mark, and he went back down for the others, who had experienced some problems of their own and switched to a longer plan, thus extending their own stops and runtime.
Once back on the pontoon, Mark gave us a superb debriefing, outlining what we had done correctly, and what we had to work on both as a team and as individuals. At this point I was feeling pretty shaken and fed up, and had pretty much decided to take the rest of the course as experience, and then take it again when I felt more ready.
Dive Two
I put the harness back where it was supposed to be, and we did a second dive, a shallower dive , concentrating on skills. This went much better, with SMB and shutdown drills behaving themselves. After this dive, I was feeling much more confident, and Mark was now able to work with me, telling me to work not only on doing the skills, but now holding the eco stops, thus maintaining better buoyancy whilst doing the skills. Masks were removed and replaced with backups, whilst maintaining trim and depth. Regs were ripped out of mouths from behind with no warning to see how we coped. We all did much better
The Saturday evening was spent in a curry house, where Garf had learnt from prior experience and stuck to very mild options, whilst others wee more adventurous and perhaps regretted it a little the next morning
Sunday
A couple of hours of theory, discussing deco theory, were spent in the classroom, before planning the third dive, the deep dive. On this one, Mark assured us that the drills would be expected, rather than suddenly finding yourself without a reg.
Dive 3 – Into the Depths
The dive was to 35 metres for 15 minutes, with stops again at 12, 9 and 6, and backup plans for longer, deeper, and longer / deeper. We overran a little on time, so I switched us to the backup plan. After putting up an SMB, Mark took it off me and I deployed a backup. Out of air and shutdown drills were done again, as was swimming along with someone else’s primary reg in your mouth. This dive was much better again, and the buoyancy was starting to come together. As Mark stated, doing these drills is easy sitting on a platform. Maintaining a deco stop when the shit hits the fan is a different story. We all surfaced in good mood as it had been an enjoyable dive. Again, a thorough debrief ensured we all knew what we had to work on. Ankle weights were removed from Nick as he was having problems maintaining horizontal trim. I was told to keep focusing on the buoyancy whilst doing the skills. More emphasis was now being placed on team work, supporting each other, and efficient communication. It’s not enough to signal a problem. Your buddy has to know which plan you are switching to, or what you need him to do.
Exams
No information on the exams. Do the course
Dive 4 – final checks
Dive four was a relatively shallow dive to 25M and then into the shallows o just carry on working on the teamwork, buoyancy and sticking to the plan. We swam along a line without masks, we dropped and picked up stages. We swapped stages around between each other. We had some problems when the SMBs turned out to be underneath the pontoon, and WreckTrekkie’s reel had begun to disintergrate after a bit of metal came off in the carpark and he chucked it under his car not realizing what it was J. Once we all surfaced we had a final debrief and then spent some time discussing kit options, and kit planning. I decided to call it a day and post the exams off to Mark as I had to drive to Lancaster that evening, so we said our Good byes and went our separate ways. To my astonishment and delight, Mark had decided that my diving had come forward so much in the two days that he would happily sign me off for the advanced nitrox and would sign me off for the deco procedures if I met him in Wraysbury to show him I had been practicing the shutdowns whilst maintaining depth. Now this, in my humble opinion, is the sign of a superb instructor, one who refuses to let students through until he is happy. I was honesty surprised it had gone so well.
Thoughts
Was it too early for me? To do deco diving, Yes. Six months practice doing drills and simulated deco until I can maintain a stop when all is going to hell is what I have decided to do until I do deco for real. The course really opened my eyes to how steep the walls of the incident pit are, and how practice is the key to safety. Was it too Early to do the course? Definitely not. My attitude to diving, my buoyancy, personal skills and team awareness changed completely in the space of two days, and I will forever more do shutdowns, practice with backup equipment etc on every dive. I wil do simulated deco stops every chance I get, and will encourage any buddy I dive with to take a more open attitude to buddy and team skills rather than being self enclosed. It was a superb course, and has been of immense benefit.
Lessons Learned
· The web is no comparison to being taught
· Real life emergencies do not happen sitting on a platform
· Maintaining buoyancy swimming along is easy. Doing it with no mask and other things going wrong is a different story and requires continual improvement and practice
· When you take a breath and someone has accidentally turned your air off, you do not thing about your alternative air source, you do not think about your deco gas. You think about the working reg you can see in your buddy’s mouth. Trust me on this.
· When you reach for something clipped on, it needs to be where you expect it and the only thing there. Get your kit config right and leave it alone. Practice with it until you can get any item ready for use with your eyes shut.
· Making an deco plan, and backup plans, takes a bloody long time with a calculator and 5 minutes with V-Planner. But know how to do both.
· Having enough air for yourself on a deco dive is nice, but have you factored in lost deco gas for your buddy.
· Chepstow is a bloody long way from Lancaster
· Don’t try to solve all problems at the same time. Chill out, and sort them out in priority. If you can breathe, you have the main one sorted. The rest can be done one at a time.
That’s it. I would recommend the course, and Indeed Mark as an instructor to anyone. I have a trip to Wraysbury in a few weeks to sort out the shutdowns and am much looking forward to it.
Regards All
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Great report! 
