Isolator knob position

[Sloth]

For those that do the "Stroke you're going to die" position have you ever given thought to the fact that if you did manage to hit the isolator that it would rotate even further back and probably out of reach. (FWIW scootering in and out of the openings on the Saskatchewan wreck off Nanaimo= Bad Idea)

Short necks, big heads, old war wounds... I'm hearing a lot of excuses.

Nah im like gumby. Ask me again when I get back in a drysuit. Probably different answer then.

Did the same thing with a wreck in Hawaii. I have no idea how I managed not shear off my isolator. It's is a risk no doubt.... dangit guess i need to get use to that stupid isolator digging into the back of my skull.

 

[ScubaInChicago]

I'm not an expert, nor am I trying to start a debate. Just a personal opinion is that if you damaged the isolator it could mean a possible uncontrollable loss of gas from both cylinders. A video I saw at 1:50 YouTube - GUE Rigging Dual Bottles shows that the isolator should be left with some play to avoid this type of failure. It makes sense to me and I would prefer to have the valve temporarily out of place then an OOG during a penetration/tech dive. I don't know how important the 10 degrees in vs. out argument is as long as the valve is accessible during a drill.

 

[MXGratefulDiver]

For those that do the "Stroke you're going to die" position have you ever given thought to the fact that if you did manage to hit the isolator that it would rotate even further back and probably out of reach. (FWIW scootering in and out of the openings on the Saskatchewan wreck off Nanaimo= Bad Idea)

Short necks, big heads, old war wounds... I'm hearing a lot of excuses.

I think this is one of those things that seems like a good idea for a variety of reasons ... until you decide to start diving in overheads. Then those reasons start to pale in comparison to the potential downsides ...

... Bob (Grateful Diver)

 

[RTodd]

I think this is one of those things that seems like a good idea for a variety of reasons ... until you decide to start diving in overheads. Then those reasons start to pale in comparison to the potential downsides ...

... Bob (Grateful Diver)

Yep, because everyone rings the ceiling at some point. The goal is not to but I have seen everyone I have ever done multiple scooter dives with hit at least once (including GUE cave instructors). And when you do hit you want the isolator to spin. Your buddies can fix that issue. They can't do anything about a leaking isolator.

Rjack. I used to tighten my isolator as well because the spinning bothered me. Get used to it and loosen that thing. It doesn't have to be easy to spin, just capable of it.

Turning the isolator down slightly reduces the risk of catasrophic hits since you are more likely to impact your tanks or first stages if you are in good trim. The isolator is the weakest point of the system. Protect it. Most people can adjust their bands/ backplate so this isn't an issue.

 

[MXGratefulDiver]

Yep, because everyone rings the ceiling at some point. The goal is not to but I have seen everyone I have ever done multiple scooter dives with hit at least once (including GUE cave instructors).

Tell me about it ... I left the plastic cap from the top of one of my MK25's somewhere in Ginnie ...

... Bob (Grateful Diver)

 

[DA Aquamaster]

For those that do the "Stroke you're going to die" position have you ever given thought to the fact that if you did manage to hit the isolator that it would rotate even further back and probably out of reach. (FWIW scootering in and out of the openings on the Saskatchewan wreck off Nanaimo= Bad Idea)

Short necks, big heads, old war wounds... I'm hearing a lot of excuses.

Gee Brian, I totally agree with you. So you might want to rethink your position as lord knows you like to disagree with me on general principle.

 

[PfcAJ]

Those are NOT dynamic o-rings and the loose isolator is no longer being taught.

Having dropped 2 sets of doubles out of a moving truck and BENT the entire manifold, its clear to see that the real risk of it leaking from impact is minimal, while scrapping a dive due to worn o-rings is certainly not minimal.

 

[JeffG]

Tell me about it ... I left the plastic cap from the top of one of my MK25's somewhere in Ginnie ...

... Bob (Grateful Diver)

I smoked a window frame of the Underwater Dam site in Minniwanka (scootering through a building.)

 

[Gombessa]

Those are NOT dynamic o-rings and the loose isolator is no longer being taught.

Having dropped 2 sets of doubles out of a moving truck and BENT the entire manifold, its clear to see that the real risk of it leaking from impact is minimal, while scrapping a dive due to worn o-rings is certainly not minimal.

This has nothing to do with isolator knob positioning, but this unfortunate result happened to us a couple of weeks ago upon the start of the dive. There were no leaks when it happened, and we didn't even notice the result until after the dive, subsequent fill, and storage of the tanks. A new crossbar was installed yesterday.

 

[JeffG]

Those are NOT dynamic o-rings and the loose isolator is no longer being taught.

Hmmmm...interesting. I'm still not tightening my nuts though.

Having dropped 2 sets of doubles out of a moving truck and BENT the entire manifold, its clear to see that the real risk of it leaking from impact is minimal, while scrapping a dive due to worn o-rings is certainly not minimal.

Its not like you sit there twisting it (the isolator) back and forth. So I don't see the "worn" oring problem.