Basic rules broken become near miss

[NAM001]

I use a scenario like you describe as a discussion point when running BSAC’s Buoyancy & Trim Workshop. I get the occasional student boasting that they don’t need dupable weight, or an secondary buoyancy device.

dupable do you mean dumpable? Not being critical just want to understand. for a set of doubles with cave fills it is easy to be carrying 20-25# of gas. the idea of dumpable weight to me seams to be more of a single tank thing than a doubles thing when it comes to managing that. that makes trimix a better choice of gas since it weighs very little compared to nitrox blends. With dumpable weight you have to be able to dump the whole gass weight 22# which is easily done with a belt but if only part of itis needed when you are looking at having say 1/2 tank gas remaining, now the belt thing is not so good. Dumping 22# makes you a cork. Again a great argument for having a dry suit when using doubles oh and we cant forget the effects of a squeezed wet suit to add another 20-30# of neg bouyancy from suit squeeze. Which again is another argument for pro dry suit. at 100 ft you can go form comfy to 40 or more neg with a blown wing. that equates to a lot of decent rate.

 

[NAM001]

Well that only rings true if your (the blanket 'your' that is) slack with looking after / maintaining your equipment. After all, simply inflate / use one wing on one dive, then inflate / use the other (back-up) wing on the next dive, etc, should at least allay ones fears of it not working from lack of use. Regular maintenance (of all equipment) is another issue altogether of course.

does not have to be slack when it comes to maintenance. I had one wing blow and it was on ly a few weks old. it got pinched between 2 tanks during transport to a site.

 

[Celt]

Diver twin 12ltr steel in a wet suit for years and never had a problem swimming them up

 

[Kay Dee]

Hi KWS,

Yes i have heard all those positions before. most teh argument is IMO based in the DIR community where now you have to either move the inflator LP hose or have an additional hose creating another failure point.

Failure point, snailuer point. And please, don't lump me in with the DIR crowd. Each to his own of course, but as Frank Sinatra sang "I did it my way" (and that even evolved over time). IMO, some folks place waaaaaaay too much emphasis on failure points as opposed to 'what works, works', and/or learning how to solve the problem should one of those referred to 'failure points' fail.

Im not saying I agree or not , just that has been the point of the opposition to using dual bladder.

Yeah, and again IMO, its a weak opposition argument at best.

The other one is that if you have a leak in one and start to get light it takes a bit of time to figure which wing is filling to correct the problem.......

Why? If your using doubles (and dual wings) you should only have one wing inflated (let's just say the one coming from the left post), so should your buoyancy fail you know right away which wing it is, so you just start filling the other wing (the one whose inflator hose runs over or under your right shoulder), while simultaneously shutting down the the valve to failed wing (if necessary). Same thing if you get a run-away-inflator on either wing (which DOES need shutting down ASAP). That is, I am I assuming you were taught how to reach back and turn off either your left or right valve / post (going to the failed wing / inflator) if necessary? Which then shuts down the gas to the dead wing / run-away-inflator and wahlah, problem solved. So at least you can fix the problem, as opposed to if, in a wetsuit, and having only one wing / bladder your now SOL, and now really have a problem. Ever tried pulling yourself up hand over hand from a deep dive using a lift bag line (with a dead single wing), steel doubles, and two or three stage bottles? Not for the faint hearted, and that lift bag better have waaaaaay more buoyancy / 'lift' than just a tubular SMB!

along with it is one more fill valve again to fail along with fill hose and but vents.

Seems your really fixate on failure points.

Again not agreeing or not agreeing just regurgitating opinions of others.

As Dirty Harry once said "Opinions are like asxxxles, everyone's got one" (including me).

As far as I know the standard is till to have the fill valve on the left. gear location is based on that such where to wear you puter etc. for most that have a dual bladder and only use one side there is a potential on not using the right side for a long time.

Well 'potential' yes, but as I said in my previous post, if that is so, then one can only blame oneself for habitually only using that one wing (inflated over left) and applying the good old Oztralian attitude of "she'll be right mate" for the one on the right.

With a dry suit you are using both devices all the time. the suit to keep the squeeze off and the wing to control buoyancy.

Correct, if diving with a drysuit and a wing, the wing is still my primary buoyancy, and if that should fail then I'll go to my ever so slightly inflated drysuit (that is only inflated enough so as not to be squashing my nuts).

With a wing you have a lp hose a fill vent valve a butt vent and perhaps more for one bladder. now you double that for the double bladder. on this and by experience you are doubling failure points.

As I said above, you seem to constantly be fixating on so-called failure points. Not a bad thing up to a point, but IMO better to learn how to solve any problem that may arise from same. After all, you can reduce 'failure points' to a bare minimum and still have a failure.

have had wings that have been compressed for some time and to inflate them the bladder insides from prior use stick together from heat and compression.

Well, correct me if I am wrong, but that sounds like you did not flush out the bladder and then dry out same properly after the last time you used them? And / or stored wing flat in interim without being partially inflated? Like I said above, or to use the acronym, PPPPPP. And that includes checking your gear yourself / and servicing when necessary.

as in another post any slack maintenance of the gear can really compound the chances of a failure. then there is the poor shop maintenance that actually caused the failures.

Agreed, and I hear you loud and clear! Hence why you should only have your gear serviced at a highly recommended shop / service facility. Or better still, take your life in your own hands, as many serious divers do, and learn (take courses) in how to properly service (as much as) your own gear as you can.

But hey, I would be the last person to ram down anyone's throat what you have to / should do, just offering my POV and some suggestions (that might be far from kosher if your a DIR aficionado).

Anyway, I am still walking and talking after 30 odd years (yeah I started diving late in life) of fairly serious (and remote) diving, and you could say I was a walking failure point at times (pick em out below). But I had no serious failures that I could not handle. Not beating my chest, just saying is all, as I dived both OC and CCR (especially CCR) solo as much as I could.
Anyway, safe diving to you KWS.

Postscript: While there are many many wrong ways to do things, there is not just one right way, as some folks / instructors would have you believe.

 

[Kay Dee]

does not have to be slack when it comes to maintenance. I had one wing blow and it was on ly a few weks old. it got pinched between 2 tanks during transport to a site.

As Forest Gump said "s@$t happens".

In the same vein, after doing all my CCR checks just prior to getting on a small private boat, while traveling to the dive site one of my CCR breathing hoses got pinched and somehow slit slightly. And although I pre-brethed the unit for a (very) short while before splashing, I did not notice it, but I certainly did as soon as I started to descend and heard the sound you never want to hear on CCR, a 'gurgling'. No problem, simply switched to BOV, surfaced, got back on boat, cut the off the short piece of hose where slit was (right near where hose entered the counterlung fitting), cabled tied (with two cable ties of course) the slightly shortened hose back on the fitting and performed the dive.

 

[Kay Dee]

Diver twin 12ltr steel in a wet suit for years and never had a problem swimming them up

So you are implying you don't us a BC or wing at all?

And if so, swimming them up from how deep and then doing how much deco?

 

[NAM001]

Hi KWS,


Failure point, snailuer point. And please, don't lump me in with the DIR crowd. Each to his own of course, but as Frank Sinatra sang "I did it my way" (and that even evolved over time). IMO, some folks place waaaaaaay too much emphasis on failure points as opposed to 'what works, works', and/or learning how to solve the problem should one of those referred to 'failure points' fail.


Yeah, and again IMO, its a weak opposition argument at best.


Why? If your using doubles (and dual wings) you should only have one wing inflated (let's just say the one coming from the left post), so should your buoyancy fail you know right away which wing it is, so you just start filling the other wing (the one whose inflator hose runs over or under your right shoulder), while simultaneously shutting down the the valve to failed wing (if necessary). Same thing if you get a run-away-inflator on either wing (which DOES need shutting down ASAP). That is, I am I assuming you were taught how to reach back and turn off either your left or right valve / post (going to the failed wing / inflator) if necessary? Which then shuts down the gas to the dead wing / run-away-inflator and wahlah, problem solved. So at least you can fix the problem, as opposed to if, in a wetsuit, and having only one wing / bladder your now SOL, and now really have a problem. Ever tried pulling yourself up hand over hand from a deep dive using a lift bag line (with a dead single wing), steel doubles, and two or three stage bottles? Not for the faint hearted, and that lift bag better have waaaaaay more buoyancy / 'lift' than just a tubular SMB!


Seems your really fixate on failure points.


As Dirty Harry once said "Opinions are like asxxxles, everyone's got one" (including me).


Well 'potential' yes, but as I said in my previous post, if that is so, then one can only blame oneself for habitually only using that one wing (inflated over left) and applying the good old Oztralian attitude of "she'll be right mate" for the one on the right.


Correct, if diving with a drysuit and a wing, the wing is still my primary buoyancy, and if that should fail then I'll go to my ever so slightly inflated drysuit (that is only inflated enough so as not to be squashing my nuts).


As I said above, you seem to constantly be fixating on so-called failure points. Not a bad thing up to a point, but IMO better to learn how to solve any problem that may arise from same. After all, you can reduce 'failure points' to a bare minimum and still have a failure.


Well, correct me if I am wrong, but that sounds like you did not flush out the bladder and then dry out same properly after the last time you used them? And / or stored wing flat in interim without being partially inflated? Like I said above, or to use the acronym, PPPPPP. And that includes checking your gear yourself / and servicing when necessary.


Agreed, and I hear you loud and clear! Hence why you should only have your gear serviced at a highly recommended shop / service facility. Or better still, take your life in your own hands, as many serious divers do, and learn (take courses) in how to properly service (as much as) your own gear as you can.

But hey, I would be the last person to ram down anyone's throat what you have to / should do, just offering my POV and some suggestions (that might be far from kosher if your a DIR aficionado).

Anyway, I am still walking and talking after 30 odd years (yeah I started diving late in life) of fairly serious (and remote) diving, and you could say I was a walking failure point at times (pick em out below). But I had no serious failures that I could not handle. Not beating my chest, just saying is all, as I dived both OC and CCR (especially CCR) solo as much as I could.
Anyway, safe diving to you KWS.

Postscript: While there are many many wrong ways to do things, there is not just one right way, as some folks / instructors would have you believe.

I have repeatedly said that i neither agree or disagree totally with the DIR concepts however many of them have proven themselves valid. I would never use 2 wings at once. In addition the issue with 2 wings is not a run away filler but the leaker that can cause the situation of having air in 2 wings and having to resolve twhere the problem resides . another point is that I would not turn off a post when I could remove the lp hose form the inflator valve easier. post shut off would only be for a leaking lp hose. I know you keep visiting the aspect over concern of failure points but I must say you seem to avoid the possibility that failure points exist and that additional vulnerable points do add to the probability of failure. All of which is really moot when doing shallow dives. My point that if you use a dry suit it makes the use of a double bladder non necessity. diving a wet suit may be a different matter. thanks for your comments.

 

[Celt]

So you are implying you don't us a BC or wing at all?

And if so, swimming them up from how deep and then doing how much deco?

No I dive dry now with a wing. This was before I got a dry suit and bcd. I was using 7mm+7mm wet suit. My twin steels were only 17 pound negative at 3000 psi. I was neutral at 10 feet with 100bar all deco was done on a weighted rope. I could swim them up from 75 meters no problem.

 

[Kay Dee]

but I must say you seem to avoid the possibility that failure points exist and that additional vulnerable points do add to the probability of failure.

Did I once say that failure points don't exist, or that I avoided them / or the possibility they may fail? I went to the trouble to try to explain that they do exist and you (the 'proverbial' you that is) should be taught how to handle them should one fail. So of course they 'exist'; and as I said even when your gear is trimmed down to the bare minimum they still exist. But they just aren't, in my own experience, the voodoo bugbear that some people make out. Each to their own of course.

All of which is really moot when doing shallow dives.

Precisely. But I wouldn't call what the OP first posted a 'shallow dive' by any means, although you may.

My point that if you use a dry suit it makes the use of a double bladder non necessity.

Agreed. But not everyone dives where wearing a drysuit is necessary.

 

[NAM001]

Did I once say that failure points don't exist, or that I avoided them / or the possibility they may fail? I went to the trouble to try to explain that they do exist and you (the 'proverbial' you that is) should be taught how to handle them should one fail. So of course they 'exist'; and as I said even when your gear is trimmed down to the bare minimum they still exist. But they just aren't, in my own experience, the voodoo bugbear that some people make out. Each to their own of course.



Precisely. But I wouldn't call what the OP first posted a 'shallow dive' by any means, although you may.



Agreed. But not everyone dives where wearing a drysuit is necessary.

both valid points in teh over relm of diving under 100 ft is really shallow ands really shallow if less than 60 ft when compared to tech diving at 200 or so

The need for a dry suit is more IMO than a location issue it is a buoyancy issue. There is always a lot of talk regarding ballanced rig etc. The concept has its problems even when all gear works. most of the issues fall on dives that are beyond single tank diving. If you need to be able to swim up with a blown wing you can do that with a single tank because if properly weighted you dont have more than 10# of gas to haul normally around 5-6 if using AL tanks you can drop a belt because it usually does not contain that much weight. ;You can put 6 in the BCD and 4 on a belt and not get into much trouble. doubles and steel tanks really changes the dymnamics of the problem and the numbers being worked with. There are many that set them selves up for failure and although they know there are potential problems in their rig they just don't believe they will get haunted by them till it happens. It was 40 years or so before I got bit. I was fortunate I had a hard bottom to work out a primary and backup solutions. BTW my buddy during that dive found that his rig could not carry both of us while both trying to swim up. It took all we had to get to a depth that our suits expanded enough to give us some lift relief.

Regards