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Advanced Nitrox & Deco Procedures course - looooong post

1581 Views 11 Replies 11 Participants Last post by  GCParris
Thursday 26th April

Prepare for course and load up car.

Drysuit – check
Cylinders – Check
Wing, Backplate and V Weight– Check
Regs - Check
Torch & Back Up - Check
Reel & Back up – Check
Spool – Check
Fins – Check
Mask – Check
Backup Mask – Arrrrrghhhhh…it’s broken…….so…..some shopping to do now!

Fri 27th April

Leaving the house at 0830 in order to be at the Aquasport in plenty of time for a 9am start. Met up with Mark, Safety Diver Ian and my buddy and co-student for the course Steve.

We filled the obligatory forms in and Mark then asked us our expectations for the course, why we were doing the course and what sort of diving experience we had.

He then explained various types of kit configuration and took us over to Underwater Explorers for any last minute kit purchases that we needed to make (I bought a replacement mask, some line for securing a boltsnap to my SPG (the o-ring snapped) and an arm slate.

After a quick inspection of our respective setups and briefing us on what we’d be doing on Dive 1 it was time to get kitted up and onto the boat.

Dive 1

Bombardon Unit

The plan was for a max depth of 15m and 30 minute bottom time.

I was to lead the dive (having only decided this on Mark’s prompting). A quite frankly rusty PADI style Buddy Check later and we were in the drink.

We dropped down onto the wreck and I prepared to lead the dive. Steve decided to pull in behind me which is something I’m not used to as I prefer my buddy by my side. I found I kept having to invert slightly or turn around to see him. It wasn’t long before an out of air was called and I reacted slowly to the sign. I also forgot to dip my head so that Steve could move away. It was only after he prompted me that I remembered.

We then had to perform a shutdown. I couldn’t reach either of the posts and could only just reach the isolator. Now I had anticipated this would be a problem as since getting my new drysuit I’ve had problems (I used to be able to do them perfectly easily before). Seeing that I was struggling and getting nowhere Mark reset my isolator and gestured that the drill was over. During the course of the shutdown I bounced my way down the wreck from 9m to the sea bed at 17m….so much for a 15m max depth.

It was then time to send up our blobs. Steve sent his up fairly rapidly whilst I was still faffing about clipping my SMB to my reel. Ascending to 9m we switched to our deco gas and then bounced back down to 12m. No confirmation of gas switch between my buddy and I was made.

My reel subsequently jammed as we ascended and so I had to leave it dangling whilst I came up the line.

The rest of the ascent was fairly uneventful except that the ascent was too slow up to 6m and too fast to the surface.

The debrief covered all of these points and more. Especially the fact that my trim was awful as I was still more diagonal than horizontal. A fact I have known but haven’t registered was an issue until Mark made some points.

I assessed that my inability to shutdown was down to my harness being too tight and so I adjusted that during the surface interval.

Dive 2


Following the debrief, review and some minor kit changes we set off for the next dive.
We dropped in and this time Steve led and I slotted in beside him. A few more skills were practiced and I tried a shutdown. After realising that I had not inflated my suit sufficiently to remove the squeeze and allow a fuller range of movement I managed to shutdown the isolator and partially shutdown the right post but I was still making life difficult for myself because of my trim.

This time it was my turn to go OOA. I signalled to him and swam toward him. No reaction. I had taken my reg out and was bubbling so that by the time he realised I was out of air I was down to my last dregs of breath.

A few more skills were practiced and it was time to send up the blob. After the fiasco of the previous dive I decided to use the spool and was not looking forward to it. Attaching the blob to the spool was a right PITA and I made an absolute hash of it. Having attached it I sent the blob up. Using the spool this time was much easier than the last time that I used it. Using the double ender as a tensioner and fulcrum around which to wind the spool works out much easier than trying to wind the line onto the spool using the double ender.

Communication between Steve and myself was improving but still required more work.

The debrief highlighted some areas for improvement including those highlighted above.

After de-kitting and a cup of tea in the café we did some of the theory and looked at the dive plan for the following day. I left Steve and Mark to discuss some other points over dinner and went home for a well earned glass of wine and some grub!

Sat 28th April

Another 9 am meet at the Aquasport to go over a little more theory and discuss plans for the first dive of the day.

It’s drilled into us that timing is crucial and that we should be diligent about making our scheduled waypoints.

Dive 3


We dropped down on the wreck and swam along the port side. We maintained close proximity throughout the dive. Steve had an OOA which we reacted well to, although once again trim went out of the window and when unhooking the long hose from under my torch I managed to rip the reg out of Steve’s mouth. We swam up to the bows and crossed over to the starboard side. Just prior to our scheduled ascent time we sent up our SMBs. Once again my deployment took some time.

Ascending to our first waypoint and the gas switch we lost about 3 minutes due to a slow ascent and some problems (Steve’s line tangled round his left post). After the switch Mark then tells us to buddy breathe which we do for a few breaths until Steve switches back to his back gas. I’m conscious that we’re behind time and trying to get us up to the next stage to remain within a reasonable window of the plan but each stop Steve calls a longer deco stop. I notice he’s flipped his slate over to one of the other plans and am confused.

When we get to 6m we’re there for an age of Sundays before I shrug my shoulders, hold out my hands as if to ask Steve what the problem is. Steve shrugs his shoulders. I turn to Mark and gesture the same. Mark shrugs and shakes his head….he doesn’t know!!

Eventually Steve surfaces saying Mark had told him he’d lost his deco gas. This was the first I knew about it although when Steve and I started buddy breathing and he stopped and switched to back gas I presumed the drill was over!

We finally surfaced 14 minutes after our scheduled run time.

We went through the debrief and lessons learned and Mark pointed out that even with the problems that we could have exited the water within three minutes of the dive plan if I had fulfilled my deco obligation and then passed the stage to Steve to fulfil his.

Dive 4

Unknown Coaster

This was to be another skills dive.

After the reel problems of the previous three dives I decided to try out my Buddy pocket reel and lent Steve my spool as he wanted to try it on this dive.

As I write this I can only remember a little of this dive.

I remember we bimbled along for a minute and then Mark instructed me to switch to my backup mask.

I removed my mask and then fumbled around for my spare mask. I couldn’t find it. I then thought of the old cup your hand and catch a bubble trick for viewing your gauges. I thought I saw something and was about to look at my gauge when I realised that my gauges were on the hand the was cupped over my eye….DOH! All of a sudden I felt an almighty tug on my fin and a dazzling light……then my head broke the surface…..oops. It was also then that I realised I’d stowed my backup mask in the wrong pocket…double oops.

I found the other’s bubbles and descended back to rejoin them. Mark told me to send up my blob. Out came the Buddy Reel…..unravelled the SMB and blew some gas into it. Pressed the release on the reel and then realised it was back to front and the handle was digging into my hand. It went up ok but I immediately realised that it was a potential death trap!

When we reached the stop depth we practiced unclipping and restowing stages and swapping them.

After preparing our kit for the dive in the morning we retired to the bar for a debrief over a beer before planning Dive 5 over dinner. Smudge and Marianne joined us for a chat and a drink and I headed home for an early night.

Sun 29th April

I had an early start to make the 0745 departure. Aboard the boat Steve and I finalised our plan and recapped the dive brief.

Dive 5

Aeolian sky

I borrowed Mark’s reel as I no longer trusted my reel or my pocket reel. Just as the boat was about to leave Steve asked if he could borrow my spool. The spool was my planned back up and the pocket reel was in the back of the car. No problem. We have three reels, what can go wrong!

Once we arrived at the site the tide was still running and continued to run when we jumped in. The swim down was long and hard with all of us having to work hard against the current. Arriving at the bottom I found myself out of breath, very nervous and unable to see more than 40cm into the murk even with the Salvo. I turned around to Mark, who I mistook for Steve and thumbed the dive. When he shrugged I followed up with a “there’s a problem” signal and thumbed the dive again. No response. Then I noticed that the DUI badge on Steve’s hood was missing. A closer inspection revealed it was Mark. I now looked frantically around for Steve. He was just arriving at the bottom of the shotline.

We swam along a couple of meters before I remembered that I really didn’t want to be here and turned to Steve and thumbed the dive. He agreed but for some reason the “I concur” didn’t register. A couple of minutes later I thumbed the dive again. This time his ok ascend registered fully.

I checked the time….12 minutes. Our missed wreck plan started at 14 minutes so it was good to use. I unclipped my reel and removed the SMB from my storage pack. I pulled a little of the line out and then noticed that it had jammed…..shit! I then decided to help Steve deploy his SMB by lighting the reel so that he could let his torch drop and use both hands. Once he deployed his line I passed him my SMB and he provided some lighting for me while I tried to untangle the line. It was no use I couldn’t do it so I stowed the reel. I looked up to find Steve had unwrapped my SMB. Double…shit. My spool and spare SMB were already connected together and so I now had to stow the SMB. I stuffed it into my crotch strap/waistband and retrieved my spool and SMB. We were on our ascent now as I needed to get above 25m before I could deploy the SMB. Then I noticed that I had somehow managed to tangle the spool line and dropped the spool. It landed 2m below me so I sank and retrieved it and shoved it in my pocket. There was still 1.5m of line hanging out of my pocket. We were down to just Steve’s reel. We were now ascending again and were 16 minutes into the plan. For some reason I managed to convince myself that we could still use the missed wreck plan but pad out the stops at 15m and 6m. What I should have done was switch back to our main plan.

We had a dropped a couple of metres on the ascent when Steve had to disconnect a jammed inflator but generally we had things back together again and the communication was getting much better.

We finally surfaced on 35 minutes. I was relieved to be up but really annoyed with myself about the lines.

Mark had planned to create some havoc with our SMBs but in the end I managed to save him the job. In fact the only thing Mark did was to entangle Steve’s right post on his line and to prompt that his inflator was jammed.

During the debrief Mark pointed out that it was like watching two people in slow motion and that part of the problem was caused by narcosis. With the low vis, current and the hard swim our susceptibility to narcosis had increased and this was evident by the errors of judgment and reduced manual dexterity.

Dive 6


The final dive of the weekend and we had a few skills we still had to complete. We dropped onto the wreck and immediately proceeded to find a visual reference that we could use to monitor each other and our buoyancy with.

We assisted each other in attaining horizontal trim and spent some time ensuring that we could feel our valves and first stages.

I performed my shutdown. It took some time and my trim was atrocious but I managed to do it so I was really pleased with myself.

I then had to complete the switch to my backup mask that I had failed on Dive 4. I was very nervous of another buoyant ascent. I removed my mask and opened my eyes. Once again the bubbles buffeting my nose was rather disconcerting but that was the least of my problems. I couldn’t locate the zip tag on my pocket! For an age I struggled to find it, then finally I traced the line of the zip and found it.

Having completed the mask removal and switch to backup we were told to wait while Mark laid some line.

A couple of minutes later he returned and told me to wait then went off with Steve. Hours seemed to pass (although in total it was less then 6 minutes) and I was growing colder and colder. I saw Ian swim past and then disappear into the gloom. Then Mark appeared and motioned me to follow. He showed me the line and then told me to give him my mask and remove my reg. I then swam the length of the line and replaced my reg as he had instructed in the brief.

The next task was, still without my mask, to remove my stage and clip it to the line then swim the length of the line and back again. When I returned there was a little surprise. Two stages! My reg I recognised and so was pretty sure that the cylinder I was looking at was mine the only way I could be sure was the clip. If it hadn’t been for the clip, which had been a PITA because it kept clipping onto the bungee on the boat, I would not have been certain that the cylinder was mine!

It was then time to send up the blobs again. I opted to go with my spool and so took out my SMB and laid it down on the wreck whilst I sorted the spool out. From the corner of my eye I could see Mark heading towards the SMB and then I noticed him stirring up the silt. I grabbed the SMB whilst I still had visibility of it! Deploying the SMB was still painfully slow but at least it went up!

The gas switch was much better this time although we kept bouncing below the 6m stop by 1 or 2 m. Our final ascent from 6m started off well but at about 3m I couldn’t dump any more air from the suit or wing and so floated to the surface.

We got back to the harbour, washed and disassembled our kit before reconvening for a bite to eat, debrief and some Deco Theory.

It’s clear that I have a few areas I need to work on before I can pass the course. The most critical of these is Buoyancy & Trim control when things go wrong or when other tasks need to be performed.

This surprised me as I always thought my buoyancy control was good…..and it is….provided that everything is going well. As soon as there is something else that requires some attention it all goes to pot.

I need to practice more SMB deployments to make sure I can do these efficiently and with little or no effect to buoyancy.

A lot of skills need to be practiced until they become automatic.

I’m planning to address the various areas of my diving that need work and rejoin Mark for another run at getting this ticket later this month or next.

Yes I’m disappointed that I didn’t get the ticket but I was pretty sure I wouldn’t after the first day and to be honest I find it reassuring that he won’t issue a ticket just because you’ve paid the course fee. It’s up to you to reach the standard…..FULLY!

Mark is an excellent trainer. Extremely patient and calm even when we wrecked all his plans! I cannot recommend him highly enough. If anyone is planning on doing a course with him I’d urge them to take up his checkout dive offer at Wraysbury on Wednesday. It will be invaluable to both you and Mark.

Thanks also to Troy, our skipper, from Breakwater Dive Centre (BDC) for being our ever cheerful taxi driver and the lad who (sorry I don’t know your name :embarassed: ) stayed late and sorted our cylinder fills on Saturday night.
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Nice write up Scuttler. It's handy to know what I've got to look forward to in July! More SMB practice me thinks....

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