BSAC

A little write up on the new(ish) BSAC CCR Full Mixed Gas Course. It's a bit long, you could always go to the summary at the bottom if you are short of time!

Last year I turned down an invitation to attend one of the pilots of the new BSAC CCR AMG Course. Having just completed a week in Hurghada on one I am pleased I waited the extra year & improved my skills sufficiently!

The theory was 'done' in the UK a few weeks prior to departure to allow maximum attention to the practical elements during the week in Hurghada.

Theory
The theory lectures are comprehensive & interesting.
The Marshalling section is perhaps the weakest lecture. Not because of the content as such, but because it reiterates a lot of general marshalling 'stuff' but in a mixed gas context. Rather like the section on marshalling Nitrox divers in the Combined Nitrox course, personally, I felt that what it was saying I would have done anyway!
However the other lectures are more focused. These where;
An introduction to the course & an overview of its scope & limitations.
Equipment & Decompression Systems. Here there where elements I knew from my OC experience as well as stuff much more related to CCR diving.
Physiology, no advanced course is complete without a section on this, again some elements from my OC experience but well worth the time we spent reviewing it.
The Decompression Theory Lecture is excellent, breaking down the different predominant decompression approaches in (modern) diving. (I put modern in brackets because Halodean Bulhman is right in there with Critical Volume Model, Arterial Bubble Model, Micro Bubbles, and RGBM etc). The support slides display each theory dynamically which really clarifies what’s going on.
Dive Planning. Planning is based around Proplanner.
Dive Conduct.
Emergency Strategies. This contained a lot of new stuff that relates to CCR diving, Constant Loop Volume PO2 operation. Linear Semi Closed is the most interesting as it is one of the procedures in the practical skills & perhaps (in my opinion) the most useable bailout mode (as long as you have planned it!). The big problem with conventional OC bailout is that for fairly conservative MG CCR dives you quickly run into the impracticalities of carrying sufficient OC bailout gas, where as SCR gives a safe sensible option (unless the scrubber or breathing loop is compromised, then you are into team/surface support issues!).


An integral part of the course is the pre dive planning (like all advanced diving courses). Following the Theory Lectures & prior to flying out to Hurghada, we had time to plan optimum gas mixes, & runtimes, including all the bailout options, for the course dives.

At this level disciplined diving is important, so computers would only be used as backup & time/depth instruments. A second depth/timer was also mandatory. All phases of the dive where to be pre-planned, descents, bottom & ascents.
(Something that was well demonstrated on one of our dives when a d*****d VR3 through a wobbly).

The great joy about diving overseas with a CCR is the issue of weight, & would the unit arrive in one piece at the other end.
In addition to getting the unit out to Hurghada, I applied some thought to what to wear. Considering the depth, duration & time of year I opted for a nice little two piece number!

Arriving in Hurghada with all my kit (Hurrah). I was picked up & deposited in my hotel. Day 1 would start in the morning.
The other great thing about 'expedition' diving is what would the facilities be like, all would be revealed in the morning.

Day1 Bumps & Grinds (or build confidence in your instructor in your ability).
After assembling kit, sorting paper work at the dive centre etc we spent the afternoon doing the basics in about 6m of water. Bailouts, buoyancy, Emergency drills (unit failure responses), stage handling, handoffs, constant volume PO2 operation, SCR operation, SMBs deco stops etc.
Basically everthing to sort yourself & kit out & allow the instructor to gauge your suitability to progress.
You always get out feeling like you've been in for 5 minutes then realise you've done a couple of hours.

Due to gas blending issues (just like real diving!), including cost & accuracy we concluded that we would need to re-plan our dives over the next few days.

Day 2 35m Dives (or, if you are going to screw up, do it shallow)
Two dives for Day 2. Both 35m, both on runtime.

Most of the action is in the ascent, although a few little drills on dive one including a few scenarios on the bottom & some constant volume PO2 drills & SCR practice.

Dive 1
Prior to the ascent we had an OC bailout which would continue to the surface, along the way (mid-water) we needed to deploy a DSMB.
Much to my serious displeasure (& embarrassment) I managed to totally screw up my first dive by swimming through my first deep stop, as I swam up the slope towards the edge of the reef, prior to deploying my DSMB.
The debriefing was not enjoyable, this type of dive I should have been able to do in my sleep!

Dive 2
Again a bailout on the bottom prior to the ascent phase, this time in SCR mode. Followed by a SCR runtime ascent.
The dive went much better, bailing out to SCR mode prior to the start of the ascent, I was unable to change diluent on the vision handset (something to look up in the manual for the following days diving). Ignoring this I continued with the runtime.

Day 3 55m Dive (things get serious)
Another runtime dive. The Ascent phase to include loop gas switches & flushes. This went well until the 15m point, I was unsure how far we were from the reef, and with the current picking up I started to deploy an SMB. Keeping to the runtime, with the loop flushes was challenging, the SMB was beginning to make things difficult. Then I had a problem with the reel. Sensibly I dropped the reel & continued the runtime ascent up the SMB line. At 9m I had time to recover the reel without messing the runtime ascent. Ultimately a much better dive, at least the runtime was accurate, although the transition from 15m to 9 had been a little too exciting.

Day 4 65m Dive
Again loop diluent switches during the ascent. Without the additional task loading of a midwater DSMB deployment, a very comfortable dive.

Day 3 75m Dive
Again loop diluent switches during the ascent. Having a reef to swim along during the decompression phase made the considerable amount of decompression very tolerable.
It was rather entertaining to see divers enter the water from one of the many moored boats, complete a dive, & a second diver enter the water & complete a dive whilst we where waiting to complete our mandatory decompression!
It also highlighted the advantage of having a reef to look at to pass the considerable time spent decompressing!


Summary
A comprehensive course with excellent support materials, both in terms of the classroom presentations & the student manual. The practical element ensures that you have a thorough understanding of the unit & the appropriate response to unit failures (most of which you should know from the MOD1 course). Additional emergency skills are introduced. Buoyancy skills are under the microscope throughout the course, as is the ability to dive accurately to runtime. Additional skills mean additional task loading, especially during the critical ascent phases of the dives. The additional equipment that is carried & used also adds to the task loading, although I found with my previous OC Trimix experience that this was a relatively minor issue.

The diving although intense & requiring a high level of skill, is not as intensive as the original CCR course I did. I think this is because you have a host of new skills to learn (& unlearn) when starting with CCR. On this course it is about precision, & mastering already established skills with a relatively small number of new skills to learn & master

Also my previous experience of OC Trimix diving meant that I was familiar with a lot of the theory & use of proplanner. Although I learnt a lot about some of the quirks of proplanner.

Evenings where spent re-cutting runtimes & confirming gas calculations. The ‘pre-planned’ runtimes that I did before flying out helped immensely, cutting down the number of ‘test plans’ I need to run to match the specification of each days dives.

Gareth Leyshon