Planned deco on a recreational dive?

[KenGordon]

There is supervision/management included in the BSAC system. A pair of Ocean Divers can dive together but under the supervision of a dive manager. That dive manager has responsibility to run a safe dive. So if their plan is 10 minutes at 45m he needs to point out the error of their ways.

Just having a bunch of people to dive with who have done it before, left alone a formal system, helps.

It might seem minor, but if I have Ocean Divers on a boat I have to plan for the depths they can do. This can be a challenge.

 

[scubadada]

They can do actual deco dives once they are qualified. The initial qualification is 20m, extended by 5m at a time over a few dives. Typically there will be a few of those before they end up able to dive to 35m depending on the sites and people diving. If a club has a number of trainees then the organised dives have to take that into account, so it is unlikely they will be doing 35m directly after qualifying. The deco will follow if it turns out to be required. Often it will be second dives that lead to the deco.

The point isn't that people go looking for deco dives to do. They do dives and some happen to lead to deco. Given proper planning and buddy procedures this is not a problem.

This is not the same as someone with 4800l of back gas and an ali80 of 50% looking to max out their bottom time at 45m. If they want to do that there are further courses to do.

Hi @KenGordon

Am I correct that a Sports Diver has not done a real deco dive by the time of certification? Seems like increasing depth and deco are a function of experience and supervision after certification at this level, is that right?

Thanks, Craig

 

[Storker]

Is there a cultural element to this? It sounds like BSAC (and CMAS?) treat divers as though they are capable of setting and following limits.

It most certainly is. In a club diving environment (my club is CMAS affiliated, but I'd be surprised if BSAC clubs were very different), you're not just assumed, but even expected to plan your dive within your limits, and then do the dive with your buddy - be it a regular one, or your buddy of the day. We don't have guides or DMs in the water, no-one is babysitting us, and no-one is schlepping or setting up our gear. We do, however, keep an eye out for each other, and if someone seems to follow unsafe practice or is diving beyond their qualifications, one of the more experienced club members - or the safety officer - may well sit down and have a chat with them. It's of course not a foolproof system, since there isn't any scuba police, and it's hard to monitor everyone when people set off in different directions with their buddy.

And this cultural difference is why I try to do a little research on the operator I'm diving with when I'm on vacation. Since I'm used to being treated as an adult and prefer to follow my own pace when I'm under water, I resent being hand-held and limited beyond my personal limits (yes, I know. I'm an old curmudgeon). And I don't like being one person in a large a group, blindly following the guide, since that means I can't stop to "smell the roses" if I feel like it.

 

[Gareth J]

Scubadada

Yes, you are correct.

During training, prospective Sports Divers are still restricted to the 20m depth limit. Progression to depths beyond 20m are only allowed once the diver has qualified as a Sports Diver.

The decompression dive during training is a simulated dive. i.e if they are not capable of holding the stop then there is no risk of injury to the student.

After qualification, a Sports Diver is allowed to increase their depth progressively to a maximum depth of 35m.

Some Sports Divers never bother with the depth progression, but these are a very small percentage. Some never wish to do dives that include compulsory decompression.
We have divers in the branch that "don't do decompression", but they will run 5 minutes of deco' without much concern. Having planned the gas required. These are generally the non-twinset divers in the branch.
Most of our divers who are qualified Sports Dives or above have some form of redundancy, more often than not a 3litre pony as a minimum.

Its a matter of what people feel comfortable with. The major difference is that they have done the theory, and the practical exercises.

Gareth

 

[scubadada]

Thanks @Gareth J that was my understanding. It's a lot different than saying Sports Divers are trained to do deco up front.

 

[Gareth J]

Scubababa

It depends on your perception of trained.

A PADI DM gets no information, or tuition, theoretical or practical of dives involving compulsory decompression.

A BSAC Sports Diver has had, theory lectures, and practical lessons.

I would say however, that the decompression theory section of the DM course is very good, far superior to that in the BSAC courses. Its only when you start doing Technical courses that the BSAC materials start to match the decompression theory in the PADI DM course.

One of the big issues when you run exped's and set the minimal limit at SD, is that there is a potential huge variation. If its your SD's you have a very good idea of who will do what, if you have guests, then it can get a bit more interesting. Some SD's will be confidently running 30 minutes or more of decompression, some would prefer to avoid doing any.

I think some North American divers get a bit of a shock diving with European divers. I do remember hearing that Gordon Smith (the KISS inventor) was shocked with how the KISS was being used in the UK. It may be an old wives tail, but I understand he was on an exped' to St Kilda (off Scotland). Got back on the boat after the dive, and was shocked that it was just him, his buddy and the skipper. When he asked the skipper where everyone was, he was told that they wouldn't be back on board for at least an hour, because of the depths and deco' they where running. Gordon was stunned and said he had never expected or designed it for anyone to use below 30m, let alone run the amount of deco time that the units where regularly doing in Europe.

Gareth

 

[scubadada]

Hi @Gareth J

I have not taken a PADI course since 2005. I have no idea what they teach regarding tables or computers regarding deco. One would think that they would teach some kind of contingency, especially with computers being so ubiquitous now. It is not difficult to deal with a very short deco obligation on your computer, at times, shorter than your safety stop or disappearing on the ascent.

Good diving, Craig

 

[KenGordon]

It's of course not a foolproof system, since there isn't any scuba police, and it's hard to monitor everyone when people set off in different directions with their buddy.

Actually there are scuba police. People have to take responsibility for their actions. If I take a an Ocean Diver on a trip when all the dives are 30m plus and something happens I'd expect to be criticised by the coroner. You operate under certain principles and if you ignore them you leave yourself open. Stuff can go wrong, but if it was foreseeable and the standard mitigations were blatantly ignored then there can be consequences.

 

[211ratsbud]

Ok, and I hope I'm not taking this out of context: said accident happened, is the troubled diver not responsible for knowing his limit and aborting ? I would hope the idea that you are able to make decisions to turn back or proceed is upon yourself, and I hope that it's taught that way.

It seems that everyone wants to instill liability on someone other than themselves, imho. If your leader takes you into a risky and untrained depth, you should be obliged to surface and never use him again! The leader should not be scott free, so I understand that it's contradictory of me to say, he should be reprimanded.

 

[DevonDiver]

That said, I believe my point is still valid, that Single tank Deco is (or should be) within the realms of the rec diver. People should be introduced to it in theory at least, rather than teh current model of No Deco, where people get into a tizz if their computer shows 2 or 3 mins of deco

The Deep Diver course includes a simulated (emergency) decompression dive. However, it's often taught really badly by instructors who have no more deco expertise than their students.

Likewise, the Tec40 course really covers all the issues raised in this thread. It works really well as an 'advanced recreational' course... and can be taught with a single tank + pony. The deco limits allowed (10 min non-accelerated) are more than suffice for adding some bottom time (especially in addition to EANx) and show divers how to plan and conduct such dives safely and effectively.

I promote Tec40 as BOTH an entry-level tech course... AND an advanced recreational course. A decent instructor can tailor it for the students needs and goals.

Both the Deep and Tec40 are 4 dives (minimum).... so they're economical for delivering the extra capacity and knowledge needed for more aggressive recreational dives.

Of course, the real benefit in these... or any... training is very instructor dependant.

Given the existence of these courses, I just don't see any excuse why 'mainstream' agency recreational divers should be doing deco without training and some prior expertise.