Split from A&I Yukon thread: Gas Rules in OW Solo Dives

[Thalassamania]

IMO anyone that thinks they need a solo diving course to be ready to solo dive, isn't ready to solo dive. Solo diving is about self-reliance after all.

Someone who insists on teaching himself may find that he has a fool for a student.

Which is fine...if we were talking about how people conduct their dives. The primary debate here however, is how an agency formulates and conducts its training courses.

Exactly.

Let me help you out. A bunch of people got really drunk, wrote down a lot of crap. Half that crap made it to the standards, was approved by people with hangovers, and the motion was carried. A certification standard is only a standard to those who subscribe to it. Get it?
They do not have to defend themselves, they wrote the standard. They will change the standard as it suits them. Debating this is crazy. If you need the "standard" to feel safe diving solo, maybe you should not be diving solo.
Eric

Gee ... sounds like you've got a lot of experience writing standards.

...

Unlike the Solo training manual, I really don't see a lot of qualifications and wiggle room here! Given this kind of language, my takeaway from the Cavern cert training - in contrast to the Solo cert training - is that the Rule of Thirds is an absolute starting point, the only deviation should be in situations where you would plan even more conservatively!

I was hoping for a gem of wisdom from the SDI rule that I was unfamiliar with. For caves the rule of thirds makes sense (as a starting point), but for solo, I still can't see it. I have no problem with people deciding to carry whatever level of reserve and redundancy they need to feel comfortable, I just operate on the basic premise that less is more, except when it's too little ... and I was hoping for an insight into what "too little" means.

Ok, thanks for the clarification - your side of the debate is clearer now.

It seems that the Solo course is a lot more vague than tech/wreck/cave courses. I always assumed that solo training would have an equally rigid doctine.

Me too.

First you're unhappy that they're enforcing rule of thirds for no good reason, now you're unhappy that they're not?

No, not at all. We were looking for a reasoned judgment for applying the rule of thirds to solo diving, in the hopes of finding a truism that we could expand upon. We were disappointed when we did not.

Perhaps more people should read the SDI Solo Diving Manual before they pass judgement. I, for one, found it well written in presenting good information, thought processes, and stressing on safety and responsibility for oneself. There was nothing that said, "thou shalt", "mandatory", or anything along those lines.

Instead, it says things like, "A properly equipped solo diver will wear the following: . . . ", ". . . one . . . thing to consider with regard to . . .", " . . . a good dive plan includes . . ."

The manual describes SDI's best practices. It is up to the diver (you know, that person that is responsible for him or herself), to take away what is important to this course.

Now, to pass the final cert dive, you do have to do a dive plan that includes you hitting the boat with one third of your gas, within the time allotted, shooting your SMB, etc . . . You have to show an understanding of what the course teaches. It doesn't come away with any "if you don't do this, you will die". [side note: My PADI nitrox instructor taught that if you break your MOD, you will die . . . ]

For me, best practice is to always dive with a buddy who is also a team member. I try very hard to never subject myself to a ppO2 that exceeds 2.8ATA. See, we calibrate our risks against our past experiences.

 

[mdb]

I much prefer diving solo and I use a 25% reserve rule personally. Cold water diving with my own equipment I have twin steel 50's. Resorts and offshore I use what they have and apply the 25% rule. If the charter requires a "buddy" I am always clear about same ocean, same day diving. It is so much more relaxing, and, IMO, safer, to just take care of yourself.

 

[Thalassamania]

While it may be safer than the insta-buddy of the day approach, I just can not see how it could be safer than diving with a well trained and well practiced teammate.

 

[FritzCat66]

The Solo Dive Planner worksheet in the back of the SDI manual calculates required gas volumes based on RMV at max depth multiplied by a "dive factor" of 1.5 to 3.0 based on anticipated difficulty, then applies the Rule of Thirds to come up with a total minimum starting volume (i.e. dive volume x 1.5 = primary supply minimum starting volume).

Minimum pony/redundant supply volume is simply set at 1/3 of the minimum starting volume. However, elsewhere in the manual (p.34) they state that a redundant source containing enough gas to make a normal ascent with safety stop from 130' using a "dive factor" of 2.0 is minimally acceptable - presuming the diver is keeping within recreational limits.

The volumes calculated by this are, of course, extremely conservative. But then, they basically encourage the diver to keep accurate dive logs and increasingly base gas consumption and planning calculations on actual experience:

"As you gain more experience building plans for solo dive excursions, draw values for [your calculations] from actual experience rather than estimates... Do this by keeping good post dive notes which compare your estimated values with actual values... you will find that things such as gas volumes in future dive plans become more accurate..."

So, again, my takeaway from this is that the Rule of Thirds, and the recommended "dive factor" as well, are only starting points until you gain more personal experience (beyond the 100 dives the cert itself requires to qualify). The manual specifically mentions, for example, that estimated average depth could be used instead of max depth "with experience".

Without having some magic formula, I don't see anything wrong with training solo divers to run their gas planning numbers on the conservative side at first, then loosening up on them as they gain more experience. I mean, what else could they really say?

 

[redacted]

I agree with you, somewhat. I'm philosophically opposed to calling something a "rule" since I find that rule implies ALWAYS, as akin to a scientific Law..

Rules have their place. They help people with limited reasoning abilities to survive.

It has been said: "Rules are for Fools."

 

[Thalassamania]

That begins to make some sense.

 

[redacted]

Perhaps to consider a rule as in 'rule of thumb' or 'guide' or principal? I'm thinking "have 500psi when you climb on the boat" is one of those 'rules'. After all, we noobs need something to go on until we've built the experience.

That is another one of those rules that has its limits that should not be overlooked. Usually there is nothing wrong with getting back on the boat with 500 psi. Unless that diver hurries the ascent and skips the rest stop so as not to violate the "500 psi rule".

 

[Jax]

While it may be safer than the insta-buddy of the day approach, I just can not see how it could be safer than diving with a well trained and well practiced teammate.

Where can I get one of those, please?

 

[redacted]

Where can I get one of those, please?

On the southern edge of BF Arizona, you are probably SOL unless you can grow one of your own. Or you can just settle on a yellow one and never be disappointed.

 

[AfterDark]

AfterDark; I'm not disagreeing with you -- you have over a thousand dives. You have the experience and confidence to dive the plan you describe.

I do not have the experience and confidence to do the same dive . . . also, where I dive are sea lions. There are only nips as interactions with people, but that doesn't mean that at some time or another a bull might turn agressive and knock me for a loop -- throw me into surge that gets me into rocks, trapped in a rock, etc.

I am simply more comfortable with a 1/3 reserve at this point in time.

So, why isn't that okay?

Whatever works for you is right for you. I do the 1/3 myself when I find a need for it.
It's just not something that everyone needs to do for every dive IMO. Gas is expensive these days and I like to get my monies worth. As you stated I've got over a 1000 dives, what I do must work.no? Have you tried poking those sea lions with a stick? I have zero experience with sea lions. I do know most wild animals don't like being touched and usually avoid humans that touch them.