DAN missed the boat ...
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JeffG
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PugetSounder
Registered
I see where you're going here, but want to caution/clarify a couple things...
1. This discussion has successfully steered away from becoming a DIR/non-DIR thread, which frankly has NOTHING to do with the merits of the discussion... let's all work to keep it this way.
2. Sounds like there is a bit of confusion on what your understanding of DIR is - example: neither the pony bottle nor the air-integrated computer is DIR, and DIR philosophy would not include looking at nitrogen-loading bars on a computer (or using a computer at all).
If you're interested, it might be worth having a private discussion with a DIR diver regarding any clairifications or questions you've got - there are plenty of them around who are happy to chat privately and provide resources for you.
The point of sticking with your training and keeping all skills current and polished is a good take-away from this discussion.
Pistol Pete
Registered
Re. DIR--convenient abbreviation, but incorrectly used. Was primarily referring to hose set-up.
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This is a lack of training and experience cluster-F, that luckily came out OK, nothing more and nothing less. When the guy felt a drag on his reg he should have looked at his gauge. Once he saw it wildly fluctuating with every breath (which I guarantee it was) he should have reached back and checked his valve. Then he could have fully opened his valve and continued on the dive, you'd never have been the wiser.
BTW: why did you two not check each other's valve position prior to the dive? Checking the SPG is never sufficient, you must check the valve position too.
ArcticDiver
Contributor
Returning to the critique of the article:
The DAN article, like most on the subject, also fails to recognize that buddy diving is a two sided affair. The positive side that there are more resources to solve a problem are often stressed. But, the negative side that there are more opportunities for equipment and human problems is often ignored; as it was in this article.
This incident illustrates how the negative side became the primary dynamic on this dive.
So, it appears to me that DAN missed the boat on multiple counts; too bad.
The DAN article, like most on the subject, also fails to recognize that buddy diving is a two sided affair. The positive side that there are more resources to solve a problem are often stressed. But, the negative side that there are more opportunities for equipment and human problems is often ignored; as it was in this article.
This incident illustrates how the negative side became the primary dynamic on this dive.
So, it appears to me that DAN missed the boat on multiple counts; too bad.
OP
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Not too sure I'd be comfortable with that. I prefer checking my own valve. My buddy may check it if they wish ... but as soon as their hand is off of it, mine will be back there making sure it's where I expect it to be.
Same goes for drysuit zipper ...
... Bob (Grateful Diver)
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We agree, I was not clear and specific enough.
ArcticDiver
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ABSOLUTELY.
The only times I have ever had my valve turned off it was done by my buddy or by a dive boat crew member.
Speaking to what the article does not address...I have lots of experience in alpine lakes where even in good visibility at 100' it is dark with a light normally required or very close to being required, very cold, and "good" viz is perhaps 20' and more likely 10' dropping instantly to zero in the immediate area if anyone stirs up the silt. Navigation can also be a challenge in the dark over a fairly featureless silt bottom.
It is not the kind of dive you choose to do lightly if your experience is 100' dives on a carribean reef with 100' viz and 78 degree water. I look at those types of dives as dives that require a bit more than the basic OW equipment as the combination of cold, depth and more importantly, the altitude corrected depth which is much deeper in terms of deco obligations.
A 100' dive at very high altitude can for deco purposes use NDL's that equate to depths well below the recreational limits with very little bottom time and rapidly mounting deco obligations. In effect, even if you plan a no deco dive, any delay on the bottom can quickly put you in a deco situation and consequently I would plan and equip for it as a soft overhead dive with a suitable redundant gas supply.
In terms of an overhead environment a suitably large pony is not as ideal as a set of manifolded doubles, but it still makes a great deal of sense. We are bashing the author for not expounding on that point, or for not further addressing the chain of events that led to the injury, but we may want to consider that the author had an editor who may well have gutted the article to fit the space available.
DAN likes to spend a lot of time on treatment and recovery phases of accidents, which quite frankly interest me very little as those facets are largely beyond my control and are for the most part avoidable with proper planning and execution of the dive. That post accident medical "this could happen to you" health terrorism approach DAN tends to use (perhaps to sell insurance) rmakes a better criticism of the article.
I do agree planning was faulty, skill levels were potentially inadequate to the task, better pre-dive planning for a potential, and even probable buddy separation would have helped, but so would equipment and configuration that was equal to the task - a decent cold water reg and a redundant gas supply to remove some of the time pressure and provide additional options.
The buddy system/communication failure here is but one part of the overall scenario and even had it worked perfectly there is no guarentee it would have prevented an accident under those conditions, in fact it could have been much worse. For example, if the other diver had a reg equally ill suited to cold water, buddy breathing at depth in very cold water would have pushed it over the edge and caused a freeze flow as well, placing both divers at risk with both regs freezeflowing. The delay in ascent by diver one taking the time to connect with diver 2 and share gas woudl have caused more icing of the reg, requiring more time to thaw would have likely left his tank totally empty well before reaching the surface. The contents of diver #2's tank may not have been adequate to get them both to the surface and certainly would not have been enough to get them through a safety stop. The consequences could have been 2 injured divers rather than just 1.
With good training some precognition and presence of mind during the event diver one may have stayed on his freeflowing reg as long as possible and not shared gas until they were in warmer water - the best shot for a buddy pair to get out of that situation without at least one bullet proof cold water reg or a redundant gas supply - and it involves pretty high level abstract thinking to recognize the potential consequences and plan for them in advance. Less ideally if the other reg was freeflow prone, they may have shared gas on the bottom and turned off the freeflowing reg - at least until reg #2 freeflowed. But anyway you slice it, whether they connected or not and whether they worked the problem to find the best possible solution or not, a large pony possessed by one or both divers would have been a much better option. Additional equipment will not prevent a mistake but it will often give you a lot more options to resolving the situation without encountering additional complications - and in some cases it lets you get your self out of the situation without endangering your buddy, whether he is still with you or not.
It is not the kind of dive you choose to do lightly if your experience is 100' dives on a carribean reef with 100' viz and 78 degree water. I look at those types of dives as dives that require a bit more than the basic OW equipment as the combination of cold, depth and more importantly, the altitude corrected depth which is much deeper in terms of deco obligations.
A 100' dive at very high altitude can for deco purposes use NDL's that equate to depths well below the recreational limits with very little bottom time and rapidly mounting deco obligations. In effect, even if you plan a no deco dive, any delay on the bottom can quickly put you in a deco situation and consequently I would plan and equip for it as a soft overhead dive with a suitable redundant gas supply.
In terms of an overhead environment a suitably large pony is not as ideal as a set of manifolded doubles, but it still makes a great deal of sense. We are bashing the author for not expounding on that point, or for not further addressing the chain of events that led to the injury, but we may want to consider that the author had an editor who may well have gutted the article to fit the space available.
DAN likes to spend a lot of time on treatment and recovery phases of accidents, which quite frankly interest me very little as those facets are largely beyond my control and are for the most part avoidable with proper planning and execution of the dive. That post accident medical "this could happen to you" health terrorism approach DAN tends to use (perhaps to sell insurance) rmakes a better criticism of the article.
I do agree planning was faulty, skill levels were potentially inadequate to the task, better pre-dive planning for a potential, and even probable buddy separation would have helped, but so would equipment and configuration that was equal to the task - a decent cold water reg and a redundant gas supply to remove some of the time pressure and provide additional options.
The buddy system/communication failure here is but one part of the overall scenario and even had it worked perfectly there is no guarentee it would have prevented an accident under those conditions, in fact it could have been much worse. For example, if the other diver had a reg equally ill suited to cold water, buddy breathing at depth in very cold water would have pushed it over the edge and caused a freeze flow as well, placing both divers at risk with both regs freezeflowing. The delay in ascent by diver one taking the time to connect with diver 2 and share gas woudl have caused more icing of the reg, requiring more time to thaw would have likely left his tank totally empty well before reaching the surface. The contents of diver #2's tank may not have been adequate to get them both to the surface and certainly would not have been enough to get them through a safety stop. The consequences could have been 2 injured divers rather than just 1.
With good training some precognition and presence of mind during the event diver one may have stayed on his freeflowing reg as long as possible and not shared gas until they were in warmer water - the best shot for a buddy pair to get out of that situation without at least one bullet proof cold water reg or a redundant gas supply - and it involves pretty high level abstract thinking to recognize the potential consequences and plan for them in advance. Less ideally if the other reg was freeflow prone, they may have shared gas on the bottom and turned off the freeflowing reg - at least until reg #2 freeflowed. But anyway you slice it, whether they connected or not and whether they worked the problem to find the best possible solution or not, a large pony possessed by one or both divers would have been a much better option. Additional equipment will not prevent a mistake but it will often give you a lot more options to resolving the situation without encountering additional complications - and in some cases it lets you get your self out of the situation without endangering your buddy, whether he is still with you or not.
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