Doing it Ridiculous

[HarryH97]

Wouldnt you also need a valve that fully opens with a half-turn?

I'm all for the ability to operate the valve underwater, I'm trying to practice as often as I can, though Im probably not as proficient as you guys.

However in the situation described where a diver who is not yet prepared to get in the water accidentally falls in, to me it is just as sensible to try to keep himself from sinking, whether by finning or ditching weight if need be AND turning on his air. Its different if a diver intentionally enters the water fully prepared (reg in mouth, mask in place etc.) except for a shut or partially open tank valve, and realizes it while at depth.

Remember it still comes back to doing it ridiculous. That also implies he's properly weighted. If he's doing it ridiculous, the only extra weight the diver carries is the weight of his/her gas. Otherwise the diver is neutral with their full kit at 5 ft without any gas in their tanks. Turning the right post (doubles) or the valve (for singles) on gives your little button on the inflator the ability to squirt some gas for lift, AND simultaneously the ability to breath off your primary. The diver should be able to get to the surface without swimming up at all. Again, this is only if they're doing it ridiculous. Swimming up is just an added bonus.

Drop the weight, its game over and time to reset...need new weight, threading, buckling, maybe getting back on the boat, etc...

If the diver did it ridiculous, checking for roll-off is standard in-water procedure and is always part of the flow check pre-descent and during manifold/reg problem solving (Valve drills). There's also some serious rubbing to turn the handwheel 3-4 times to close the valve. Maybe its high time to re-exam your bouyancy and trim in shallow waters (1-2 ATAs). The primary should be harder to breathe as the valve closes. At which point, you just reach back, turn the valve back on all the way, avoid hitting the ceiling, and continue diving.

Again, this all hinges on doing it ridiculous and not being overweighted. Most people think diving a set of doubles in the first 4 ATAs is ridiculous. Let me say this...they have not even begun to fathom true ridiculousness! Just do it!

Sincerely,
H2

 

[waynne fowler]

All good points, well taken. :05:

I never thought of the delay in ditching when horizontal, though I think being horizontal is unlikely in scenario 1).

If scenario 1) happens to me, even assuming I go for the valve, at the same time I think i'll be trying to fin up by instinct (which should be easy unless one is overweighted) or if needed, ditch weights. I can think of some sites where I can get too deep quickly and possibly have bigger problems.

In scenario 2), yes, the simple and quick solution is to turn on the valve, no argument on that.

I fully agree with you and I have always contended that problems that occur underwater can and should always be resolved underwater. Its just that I consider scenario 1) as a surface problem that can (also) be solved by establishing positive buoyancy.

No question that both could be resolved with weight dumps.

Yes falling in the water in perfect trim is quite a reach, unless your just cool like
that :14:

Happy Turkey day all.

 

[waynne fowler]

Very insightful. Come on admit it, you had help didn't you?

Edit...read what I wrote and it didn't look too good. That was a joke...now laugh every one so I don't feel bad and have my holiday ruined.

:lol2: :yelclap: :lol: :rofl2:

Feel better?



Happy T. Day

 

[Bruciebabe]

.
Now as for roll-off, this only happens on the right post in overhead.

Not wishing to be a pedant but also wanting to Do it Right. It is your left post which rolls off. I have JJs book in front of me for reference. Hence the left post has the necklace and SPG both of which you can live without. The right post, which would roll on, has the primary long hose and the LPI for your BCD, both of which are mission critical.
It is suprisingly easy to roll off your left post in a tight cave which is why some people fit cages over their regulators, though GI would throw his toys out of the pram if he saw you with one of these.

 

[MikeFerrara]

Not wishing to be a pedant but also wanting to Do it Right. It is your left post which rolls off. I have JJs book in front of me for reference. Hence the left post has the necklace and SPG both of which you can live without. The right post, which would roll on, has the primary long hose and the LPI for your BCD, both of which are mission critical.
It is suprisingly easy to roll off your left post in a tight cave which is why some people fit cages over their regulators, though GI would throw his toys out of the pram if he saw you with one of these.

Just to add a little. The main reason we (not just DIR but most divers who use a Hotharthian like configuration) run the backup off the left post is that if we donate gas it's with the long hose off the right post. If we are traveling through a restriction the OOA diver will be in front and his post (the right one) will roll on. The one we're breathing (the left) can roll off. The advantage of this is that we'll know if it rolls off and just reach back and turn it back on. If the OOA divers post rolls off we don't have any way of knowing and in a restriction he may not be able to tell us. Of course besides that, the last thing an OOA diver needs is another OOA.

I haven't seen many divers using cages but a few. Though we try to avoid it, bumps can happen in tight areas but most of the cave we dive in doubles is plenty big. Restricted areas are limited and I just check valves while in restrictions and when I get out. In general I fondle my valves quit a bit just checking the position of the valves and my range of motion. I just do it as I go without slowing anything down, interupting the dive or really even thinking about it. It's just habit.

 

[HarryH97]

Not wishing to be a pedant but also wanting to Do it Right. It is your left post which rolls off. I have JJs book in front of me for reference. Hence the left post has the necklace and SPG both of which you can live without. The right post, which would roll on, has the primary long hose and the LPI for your BCD, both of which are mission critical.
It is suprisingly easy to roll off your left post in a tight cave which is why some people fit cages over their regulators, though GI would throw his toys out of the pram if he saw you with one of these.

You are absolutely correct. My mistake. I just wanted to say that roll-off ,which occurs on the left post (back-up) and not on the right, is not really a big deal as turning a valve should be as simple as checking your SPG. Perhaps even simplier. Putting cages is just unnecessary and not part of the ridiculousness.

Sincerely,
H2

 

[lamont]

How come the left post isn't reverse threaded to prevent left post rolloffs?

Bozanic is apparently agitating for this and other changes:

http://www.iucrr.org/manifolds1.htm
http://www.iucrr.org/manifolds2.htm

I won't go into some of his logic or conclusions in there, but specifically, why not reverse thread the left post?

 

[markfm]

Any chance it's a pure cost issue? Starting from a relatively low volume sport, to then add a reverse threaded valve, still machined to high quality, might drive tanks and valves through the roof.

 

[MikeFerrara]

Just realize that Bozanic is only speaking for himself here. There have been manifolds with metal knobs and there manifolds that have hard plastic knobs. We replace those with the knurled soft rubber sherwood type. they can crack and break off leaving you with nothing to turn! It's also a pain to grip and turn turn slick knobs with gloves. Though I've never used one of the metal ones the complaint I've heard is that they can dent making it so they can't be turned. I was in Florida diving and had a guy show me something he had put onto his left post valve to prevent it from turning. I don't really remember what it looked like other than it was some kind of cover that would spin and not turn the valve. I thought it was a stupid idea and never made any attempt to get one for myself.

I don't want a reverse thread because then every one has to relearn the righty tighty lefty loosy thing and it would cause more problems than it could ever solve. Without knowing the exact manufacturing processes the valve manudfacturers use, I'd have to think that a reverse thread would be a simple very low cost tool/process change. It's just a stupid idea, IMO, and they'd probably only sell one (the one that Bozanic wants).

Propper use of the isolator is a skil/discipline issue that isn't a problem for most folks and there are probably still non-isolated manifolds floating floating around for those who would like to use them.

Roll offs just aren't a big issue for lots of reasons including but not limited to...

Turning it back on is easy and any overhead diver should be able to do it easily. Checking the valve reguilarly and especially in and around restrictions or after being bumped should be habit. Roll offs are and should be rare because divers shouldn't be hitting their equipment against the cave and divers wearing doubles shouldn't be spending mych time in cave that's too small for them. There's other equipment that can be used for small cave like side mount.

Also note that Bozanic's account of the one incident suunds like the primary was comming off the left post...don't do that!...for reasons stated earlier.

There are those who think you're better off without an isolator and those who prefer independant doubles rather than manifolded. Those folks can do as they wish but the isolated manifold we have today is essentially what's been chosen after lots of cave diving. Bozanic seems to think it needs to be redesigned but I don't know who would agree woth him...I know I don't.

 

[divealaska]

Sad story about the diver fatality. The Agency that trained me would not advocate an air-share in this case but rather a right post shutdown and switch to the backup reg. I wonder what training this diver had...
Once an air-share is initiated the donating diver has very little to do that is more important than gas management including frequent "flow-checks" where the valve positions are confirmed. Interesting that the first diver continued to swim on despite the reg being pulled from his mouth. Shame...