[Mark Chase]

Having logged 26 hours in the UK on the unit with 16 in the salty stuff and 10 in puddles Andyp and I set out for the Red Sea in search of serious hours and multiple dives on the box. The experience of a solid weeks diving threw up some interesting issues and open up my eyes a bit so for the sake of the interested and the potential CCR boys and girls here’s an account of some of the things we had to deal with:

Feel free to slag me off I deserve it..

TRANSPORT

We booked tanks with the dive centre to keep the weight reasonable but it was still a problem. I took off the control head and hand sets and put them in hand luggage. That left me the basic unit without tanks in the APValves box. I packed the scrubber with 2.2Kg of Sofnalime and put that in the unit and I packed the hoses, 0 rings and scrubber holder in the back case held in place with gaffer tape. The unit was then wrapped in two 5mm wet suits.

Total shipping weight 31.4kg (Ignoring head in hand luggage) including the wet suits.

I am told the black and yellow box is similar to a transport box used on aircraft so I marked it up with BIG stickers with my name address, International mobile phone number and my destination.

I estimated 15kg of lime would be needed for the week with a 4hour run time on each fill. The remaining Sofnalime was packed in 2ltr lemonade and water bottles and in one 5ltr can. These went in main luggage.

Remember to print out the transport document for the lime out of the APD manual.

SPARE PARTS.

Two spare batteries
One spare 02 cell
A set of 0 rings
Tube of 02 grease
A dash of Buddy Clean


PROBLEMS ENCOUNTERED DURING THE WEEK

The usual neg pressure failures for me but that’s about it for the unit.

VR3 link failed, I believe due to corrosion in the fisher connector. My fault for not rinsing it after every dive.

Andrew had a faulty first stage on the dill side, which caused the interstage pressure to rise to 11 and result in bubbles leaking from his auto air. We cannibalised my off board bail out TX40 and used this first stage to run the unit.

Andrews auto air sprung a major leek and we took it off and replaced it with my TX40 reg and a borrowed wing inflator hose.

Andrews VR3 link also failed for reasons believed to relate to water in the cable.

Andrew left his handsets on by mistake and had to use fresh batteries during the trip

The green O2 label fell of my o2 injector button


LOGISTICS

Sand sand everywhere. Where there wasn’t sand there was grit. It proved very hard to keep it out of the unit. I found sand in the top of my O2 feed on the scrubber and it was always present in the mouthpiece.

I pored my buddy clean into Andrews bottle and filled my bottle with liquid soap to allow spray testing for leeks. This proved an essential bit of kit to have.

COCK UPS

Andrew and I have been used to spending loads of time prepping the unit the night / day before a dive and then doing the pre-dive checks on the boat. Doing two / three dives a day, every day in the red sea lead to complacency on my part and problems keeping the units running. Here are a few of the issues we encountered.


LOST LEAD

We were using lead blocks instead of our normal shot bags to weight the unit. The quick release weight pouches provided by APD are crap and on the first dive I lost two blocks of lead when the zips came undone and the blocks fell out during the dive. Fortunately with 30m viz we found them and I put them back in.

Shot pouches tend to stick in better but the lead blocks are like Houdini. Andrew also lost a lead block during a dive. The weight pouches are hung in such a way as the blocks fall forward against the zips. The zips come undone far to easily.

To overcome this problem I cable tied the zips shut. I had no further loss of weight after that.


O2 SWITCHED OFF

The units were prepped, calibrated and pre-dive checked in the dive centre then packed in the APD crates for transport to the dive site. Journey time was generally 15mins over very bumpy roads / tracks. I tended to switch the handsets off after calibrating and switch them on again whilst kitting up. I left the gas on. Andrew preferred to switch his gas off. When helping me pack my unit into its crate for transport he switched my gas off and told me he had done it to stop me losing gas in transit. I actually watched him do it.

Once at the dive site I kitted up and switched on the unit. The handsets hit 0.7 and the solenoid fired OK so all was cool to go. We walked the 100 yards or so through the water out to the entry point. I checked my handsets again and they were at 0.6. The solenoid was firing so all was well. I pre breathed the unit all the way out to the entry point.

I just made it to the entry point when the red lights on the HUD went solid red from a red green flash typical of 0.7 at ambient. Just as I checked the handsets the warning buzzer went off. The handsets said 0.2pp02.

I had forgotten to turn on the 02 and the residual pressure in the 02 circuit had managed to maintain set point for a couple of min's when I first checked the handsets. No big deal I reached back and switched the 02 on and the handsets settled down to 0.7 pretty quickly but a good reminder as to how important pre-breathing the unit for 5mins really is.


NARCOSIS

On a dive called the canyon you drop in a crack in the canyon ceiling at 20m straight down another 15m to the seabed inside. On my decent I was dropping too fast and the HUD alerted me to a rise in PP02. I checked the handsets and they had spiked to just over 1.5pp02. I breathed out through my nose and sucked in some dill to drop the PP02 but at that point noticed my VR3 was showing a Ppo2 of 2.05. I was at 34m and although the slave and master were showing PP02 of 1.4 and dropping I decided to dill flush and check the handsets.

Cock up 1 I didn’t switch to low set point prior to doing this. Andyp said we were told this on the course but I had totally forgotten. As a result as fast as I flushed the solenoid injector was fighting to get it up to 1.3 so the numbers were ever changing. I got confused as to what my PP02 should be at 34m on air dill and I realised I was too narked to do the math reliably.

I showed Andrew the VR3 to explain the situation and we ascended to 20m where upon my head cleared enough to do the dill flush and work out what my resulting PP02 should be. That said I still forgot to drop the set point to 0.7 so I used a shed load of dill to confirm the numbers.



INADIQUATE DILUENT

On the above dive I went in with just over 100 bar of dill. The dive up to and including 3 diluent flushes cost me 70bar of gas. I had 30bar left for suit inflation wing inflation and to bail out to should I flood the loop. I got so used to using 30 –50 bar of dill on a dive that I didn’t bother toping up the dill before the dive and this was a stupid mistake, as I had no other form of bail out.

INADIQUATE 02

Grabbing the chance of an extra dive I set out for the Islands an 18m bimble around a very pretty reef. Having got to the dive site I do my pre-dive checks and to my horror I find I am left with only 30bar of 02. I did the dive anyway and managed nearly 50mins on a 0.7 set point before the needle got to a point where even I wasn’t stupid enough to carry on. Then I switched off the handsets and ran the unit semi closed to end the dive. This was no big deal but a good reminder as to how easy it is to forget to check your 02 and dill levels on a multi dive trip. The OC people wont understand this as the SPG is such a crucial bit of kit but for CCR you hardly use any gas and it’s easy to forget to check them. In fact it’s easy to forget you need gas at all.

LOOSE MOUTHPIECE

On the way out to the Canyon my mouthpiece fell off for no particular reason. I hadn’t snagged it or done anything odd apart from twist the breathing loop hose to get rid of kink. First warning I had was when I sucked water instead of air. Despite the cable tie being where it should be it had not been done up properly and it was possible to just pull the silicone mouthpiece off the loop. I had never checked this before but after reassembling the unit it was obvious that even a light pull on the loop would result in the mouthpiece falling off. That would have been a very very bad thing to happen on any dive.

FLOODED COUNTERLUNGS

After the above incident I cleared the loop into the counterlung and continued the dive. Here was a fair amount of water in the lung but no gurgling from the scrubber so I wasn’t unduly concerned. However I dipped my head to look back between my legs to find Andrew during the dive and a shed load of water came out from the lungs and back into the loop. The deep gurgling was unlike any drool related event I had experienced before and was a bit scary. After quickly emptying the loop back into the lungs I made a point of NOT dipping my head again.


SCRUBBER DURATION

So when exactly did I change the Slime???? Once I was prepping the unit and I suddenly thought about a fill change? I couldn’t remember when I had last done it. Andrew and I went through a quick recap of the last few dives and toted up how many hours we had on the scrubber and all was well again but in the future I will mark the dive times on a log or on a bit of type on the scrubber housing so I don’t forget.




So that’s about it. I learnt a lot and had some big wake up calls but all in all I felt progression after the weeks diving. Its very easy to fall into holiday mode and forget your normal routines and cautionary checks. Unfortunately CCR is not a forgiving as OC so on our next trip in Feb I aim to be more disciplined and regimented in my approach. I also aim to have PP02 tables available for the planned diluents.

My conclusion of the trip was the CCR was a PITA to dive on the bimble dives but a great tool on the deep stuff. I thought I would gladly swap my unit for a single tank and BCD for most of the dives but then I stuck the OC bailout reg in to remember what it was like and I nearly ruptured my eardrums. SO perhaps CCR is worth the extra effort after all.

ATB

Mark Chase