New Acc Deco Procedures Course

[Matt Smith]

BSAC have announced a new accelerated deco procedures course at the DOC 09. I am eagerly awaiting roll out with the intention of doing the course in good time.

I had been expecting this to teach and certify the use of up 100% 02 for acc deco and was disappointed to hear that as usual BSAC has stuck to their sometimes over-conservative policy and as such this course certifies up to 80% Nitrox use for decompression then stop.

Other agencies will certify use of up 100% 02 at this level and quite correctly so IMO. By the time a diver has reached this level I am certain they are self-sufficient & responsible enough to use 100% 02 safely.

I am not unhappy with BSAC but isn't it time the organisation produced a course that directly competes with commercial competition?

thoughts please!

[Nigel Hewitt]

I had been expecting this to teach and certify the use of up 100% 02 for acc deco and was disappointed to hear that as usual BSAC has stuck to their sometimes over-conservative policy and as such this course certifies up to 80% Nitrox use for decompression then stop.
<holds head in hands>
I thought we had got rid of this 80% lark years ago.

By all means explain the advantages of 80% but give the poor guys a card to buy up to 100% because it is so much easier to manage. Topping half a tin of 80% back up to full needs a stready hand because you're on the cusp of the gas laws. There will be days when 100% is a better choice or maybe the blend came out high.

[steve6690]

BSAC have announced a new accelerated deco procedures course at the DOC 09. I am eagerly awaiting roll out with the intention of doing the course in good time.

I had been expecting this to teach and certify the use of up 100% 02 for acc deco and was disappointed to hear that as usual BSAC has stuck to their sometimes over-conservative policy and as such this course certifies up to 80% Nitrox use for decompression then stop.

Other agencies will certify use of up 100% 02 at this level and quite correctly so IMO. By the time a diver has reached this level I am certain they are self-sufficient & responsible enough to use 100% 02 safely.

I am not unhappy with BSAC but isn't it time the organisation produced a course that directly competes with commercial competition?

thoughts please!

I haven't seen the new syllabus yet, but it seems that AN divers will have to pass the Bouyancy Workshop at Gold standard ie +- 0.5m as part of their upgrade path. IMHO a AN diver who can hold a stop to that level, without a fixed reference point, should be able to safely use 100%.

[Dave Woodward]

l am not too bothered about the 80% thing, though 100% is more convenient for handling, filling etc. that would be my only real gripe with it. Hopefully I will get hold of the manuals sooner or later as we will most likely be running one this next year.

I am sure it is an improvement on what we had before although I can't wait for the popular judgement on Accelerated Deco tables based on the BSAC 88s.....

Maybe they'll change it 100% further down the line like they did with ERD, but got to remember this isn't an ERD course or ERD level. I thought IANTD were still at 50% luddites...

[MattS]

I haven't seen the new syllabus yet, but it seems that AN divers will have to pass the Bouyancy Workshop at Gold standard ie +- 0.5m as part of their upgrade path. IMHO a AN diver who can hold a stop to that level, without a fixed reference point, should be able to safely use 100%.Are the new tables still based on a 6m last stop? Is CNS exposure limited to 80%?

+ Breathing 80% at 6m + 1m gives you about 2Hrs before reaching 80% of the CNS clock.
+ Breathing 100% at 6m gives you about 35 minutes.
+ Breathing 100% + 0.5m triples the CNS%/Min figures, about 12 minutes.

The difference 100% over 80% makes to the decompression obligation is, hardly any.

Gas logistics should not be a huge problem. It would be a fairly rare situation to be filling open circuit cylinders without some means of topping off the O2 with air.

Personally I would say that 80% is a good choice for the target audience of progressing Sport Divers. Certainly it is the choice I make for bobbing up and down under a delayed in the channel on open circuit. Also, when diving CCR a 1.3 setpoint is near enough 80% at 6m.

[steve6690]

Are the new tables still based on a 6m last stop? Is CNS exposure limited to 80%?

+ Breathing 80% at 6m + 1m gives you about 2Hrs before reaching 80% of the CNS clock.
+ Breathing 100% at 6m gives you about 35 minutes.
+ Breathing 100% + 0.5m triples the CNS%/Min figures, about 12 minutes.

The difference 100% over 80% makes to the decompression obligation is, hardly any.

Gas logistics should not be a huge problem. It would be a fairly rare situation to be filling open circuit cylinders without some means of topping off the O2 with air.

Personally I would say that 80% is a good choice for the target audience of progressing Sport Divers. Certainly it is the choice I make for bobbing up and down under a delayed in the channel on open circuit. Also, when diving CCR a 1.3 setpoint is near enough 80% at 6m.

Absolutely, but I can't see the point in not certifying the diver to use up to 100%, as per TDI Advanced Nitrox, IANTD Advanced Nitrox etc. Most divers I know didn't bother with tables after their AN course, but then again they do accelerated deco too - allegedly. As for the CCR thing, isn't it a pre-requisite for MOD 1 that you need to be certified to use 100% ?

[Mark]

As for the CCR thing, isn't it a pre-requisite for MOD 1 that you need to be certified to use 100% ?

I did my MOD1 only holding BSAC advanced nitrox...


:)

[Nigel Hewitt]

As for the CCR thing, isn't it a pre-requisite for MOD 1 that you need to be certified to use 100% ?I can't remember what Nitrox card I offered. I had several but it was probably my PADI one as that was the one I kept in my wallet.

I learnt more about real world nitrox doing CCR MOD1 with Dave Crockford than anybody had ever told me before.

[Janos]

Are the new tables still based on a 6m last stop? Is CNS exposure limited to 80%?

Yes & yes.


Personally I would say that 80% is a good choice for the target audience of progressing Sport Divers. Certainly it is the choice I make for bobbing up and down under a delayed in the channel on open circuit. Also, when diving CCR a 1.3 setpoint is near enough 80% at 6m.

Personally I think 50% is the best gas for a single mix.

Janos

[Janos]

As for the CCR thing, isn't it a pre-requisite for MOD 1 that you need to be certified to use 100% ?

No. I couldn't use 100% when I did my Mod 1.

Janos

[MattS]

Personally I think 50% is the best gas for a single mix.I have pretty much settled on 80% for deco, after diving the length of the local slack in the 25m to 50m range. I never really got on with accelerating deco on < 70%. I prefer to carry out the bulk of my stops between 5m and 3m. The PPO of 50% in the shallows is not so high that I completely trust it, to drive efficient accelerated decompression, after a lengthy bottom time.

I did some 3 mix open circuit Trimix diving, but couldn't really afford to do it too often and never bothered with Normoxic. My main use of 50% has been as a safety gas, breathing it on an air table. Although I did once do the Blackhawk in Warbarrow bay on a borrowed stage of 50%, due to a misunderstanding between a blender and my manifold.

If 50% suits you and your diving...I guess the new course does qualify for 50%?

[Gareth]

If 50% suits you and your diving...I guess the new course does qualify for 50%?

Yep

The tables provided cover bottom gases of Nitrox 21, 27, 32, 36, with decompression gases of 50 & 80 %.

If you are using a computer you can use any bottom gas upto 50% & any decompression gas upto 80%.

The feedback I had from the pilot course was extremely positive. The 100% Oxygen is a no issue as far as I am concerned. By the time its an issue you willl have done the Sports[1] mix (50m limit), which has replaced the ERD course (which was the 100% O2 qualifying course). Remember, this course replaces the ANx (although there is significantly more in the ADP than the old ANx). I would prefer people to think of this as a 'diving course' not a 'technical course' [2]. The 'technical' courses start at mixed gas or CCR. Although as Mike (Rowley) explained this is now (or will be) the foundation course for all technical courses.
The skills knowledge & techniques taught on the course will complement & improve anyones diving from passionate wreck divers to underwater photographers.

Using rich Nitrox mixes relys on the individual having good bouyancy skills. The Gold standard ensures those entering the course have sufficient skill to complete it, and avoid disapointment.
A large part of the open forum discusion (at DOC,) related to poor bouyancy & how we push to improve this throughout the orgainisation. Whilst there are branches & individuals with excellent skills & standards, there is huge variation, as will be testified by any ANx Instructuctor who has taught a ANx SDC regionally.
The Bouyancy course can be taught in branch. There is not really any reason that this should cause any impediment to those wishing to progress on to the ADP.
Even with this, I would not be surprised if on a regional course, there is a 'slow' stream, redoing the sheltered water skills of day 1 on day 2. I would be very happy to be proved wrong on this, but I some how doubt it.
There is an element of task loading built into the course, this is intended to, as much as possible, to ensure individuals have reasonable bouyancy skills!
The entry requirement is Sports Diver, with 20 dives & experience in the 30m zone makes this an extremely inclusive course. But with that there are the associate problems, the gold bouyancy requirement helps minimise them.

What is amusing for me, & probably disapointing for those that have developed the course, is the level of critisism the course is getting from those who have either, not experienced it, or seen the student/instructor materials.
Whilst inevitably there will be those that will be unhappy with the course, I predict the vast majority will be more than happy (judging by my experience of the course).
That said. All the authors of all the courses welcome feedback, both positive & critical. They need this to improve the quality of the courses & ensure they meet changing requirements.


Gareth

[1] Can never remember if its Sports mixed gas, then Recreational or Recreational followed by Sports.
[2] I don't really like the term technical.