Getting back to the point of this thread ...
I was reading in a magazine about technical diving and being able to properly plan dives. Based off of what my PADI OW book states and my actual course (3/5 modules completed), I was wondering- why isn't air consumption and decompression something more focused on? Is it and I'm missing content from a difference of instructors or dive associations? It feels pretty basic in knowledge to be able to plan a dive from beginning to end in a very thorough manner with even just a basic level certification.
Let me elaborate below:
So far from what I'm both reading and being told air consumption and decompression isn't a large focus of just basic open water certification. You learn about staying within NDL and to always keep an eye on your SPG but the magazine I was reading had it right I think. A large separation between rec and tec divers is planning and knowledge. It may just be my anal will to learn and know everything about what I'm doing, especially in dangerous settings but I'd like to be able to plan out a dive and be able to appropriately troubleshoot (ie. reaching into decompression stops) most problems. I know that as a common article OW certified divers aren't supposed to have to worry about decompression if they're being smart and following the dive tables- but would the knowledge ever hurt someone? I'm trying to look at this as more of a planning empowerment situation over one to empower dangerous stupidity in testing boundaries you're not supposed to be inserting yourself into. As far as air consumption goes I think it would be kind of neat to start scuba knowing what your consumption is and to be able to improve it and see progress and at a later point if possible, plan more dives with the same tank air permitting (ie. I go for 30mins at 40ft and consume 1/3 a tank, I'm able to then logically calculate I'm able to safely squeeze in x amount of time at x depth on a single cylinder).
Just a few noob thoughts, not trying to start a certification flame war depending on peoples preferences. *puts on learning cap*
Zack, the reasons why more gas management isn't taught at the basic level ... and this applies to most agencies, not just PADI ... are various. You've heard some, which have to do with the course length, the amount of material already covered, the market demand for this knowledge, and the fact that since this information isn't taught at ANY recreational level in many agency curricula, there's a distinct possibility that your instructor never learned it.
I have spent the better part of eight years traveling around my local area ... basically anywhere I can drive to within a few hours ... giving free seminars on the subject of gas management. I've met dive instructors and course directors who've told me they never really thought about it. I've had not-yet-certified students attend and completely "get" the concepts. It isn't difficult to learn ... it's just that, in the current mode of dive training, reactive gas management seems to be easier to teach than proactice gas management. In other words ... "watch your gauges" and "end the dive with 500 psi" seem to be the prevalent thought process of most in the dive instruction business.
Someone earlier posted a link to the gas management article on my website. I encourage you to read it, and feel free to PM me with any questions it may cause you to consider. What I tell folks in the seminars is that I'm not expecting them to run the math every time they dive, I want them to start changing how they think about dive planning ... because gas management IS a part of dive planning ... and consider how much gas you have BEFORE the dive, rather than waiting to think about it until after the dive is underway. A fundamental part of dive planning should always be to assure yourself, before the dive begins, that you are carrying adequate gas to do the dive you're planning to do.
As for my own classes, I introduce the concepts in OW ... but do not spend a lot of time on gas management until AOW. I do it this way for two basic reasons. First, because at the OW level I want my students to focus on the basics of buoyancy control, awareness, and proper trim. Learning to dive involves not just singular skills, but the ability to combine those skills in an environment you've never before been exposed to. This requires some fundamental behavioral changes ... as an example, putting on a mask greatly reduces your ability to see what's going on around you, and you have to learn to move around more to see what you've always been able to see with peripheral vision. Because this involves a behavioral change, a lot of people don't do it ... and the usual result is a buddy separation at some point, until the new behavior is learned. So for this reason, at the OW level, I encourage students to dive conservatively, be aware of your limitations, and give yourself a large safety margin until you gain more experience and knowledge.
At the AOW level, gas management makes more sense ... because that is where you are introduced to deeper, more aggressive dives that will cut into your safety margins and require more knowledge of appropriate reserves for dealing with unexpected problems. Furthermore, by the time you reach AOW, you will have at least enough dives under your belt to be able to make reasonable measurements of your actual gas consumption rates ... your "miles per gallon", as it were ... and therefore be able to make use of the techniques used to calculate how much gas you'll need for a given dive. My students, prior to their deep dive, are required to calculate how much gas they'll need for the dive plan. It's often at that point that they realize ... without my needing to tell them so ... that the AL80 they've been diving with isn't adequate for the dive they're planning to do. They then have the tools to make better decisions about whether to either shorten the dive, reduce the planned depth, or opt for a larger tank.
I congratulate you on thinking about this ... most divers don't. The first time I offered a gas management seminar, only two people showed up ... TSandM was one of them. Since then I'm happy to say that more and more I fill rooms with people who are thinking about this topic. Even happier to say that some other instructors are now teaching it, and a couple in my area are even offering seminars of their own on the subject. This makes me happy, because to my concern this is the single most important topic that usually gets overlooked in typical recreational dive instruction.
There should never be a reason for running out of air at depth ... and I look forward to the day when the dive instruction community puts as much effort into teaching people how not to run out of air as they currently put into teaching them how to react when they or their dive buddy do run out.
Proaction is always better than reaction ... you have my respect for being proactive ... it tells me that you have what it takes to become a very good diver ...
... Bob (Grateful Diver)
Seriously this so far off the mark that I think you put this in as joke. No one in their right mind would plan for 10 stops on a 30 metre dive. I fail to see the rational in so many stops. The whole point of no-decompression diving is that the slow ascent is washing off what minimal deco you have incurred. This can even be achieved by the polaris like 18mpm ascent rate stipulated in the RDP.
I bet at least a few times a year in resorts someone goes too deep away from their party for just a bit of extra time, runs out of air and needs a buddy assist because they weren't checking their gauges and didn't know exactly what they had in air and time. I'd think also knowing this would encourage checking SPG's more often too knowing your time limit, no?
