Manifold shutdown procedure

[scubafool]

OK, so I did have somewhat of a handle on the benefits?

If so, then while your method of diving with a closed isolator DOES require more attention to detail (ie watching to different SPG's) & more tasks (ie switching second stages), it offers some of the benefits of independant doubles (ie no gas loss whatsoever from at least one tank if there is a problem with anything on the other tank). It also offers the benefit of being able to breathe ALL of your available gas from either regulator in the event of one of them failing.

How's I doin' so far?

 

[wedivebc]

OK, so I did have somewhat of a handle on the benefits?

If so, then while your method of diving with a closed isolator DOES require more attention to detail (ie watching to different SPG's) & more tasks (ie switching second stages), it offers some of the benefits of independant doubles (ie no gas loss whatsoever from at least one tank if there is a problem with anything on the other tank). It also offers the benefit of being able to breathe ALL of your available gas from either regulator in the event of one of them failing.

How's I doin' so far?

I would say you got it.

 

[OneBrightGator]

One of the big problems I see with independents is while you will have saved a third (equal to the amount used to get in) if you have a complete failure on one of your posts/tanks as anyone who's taken Intro has seen it can take much more gas to get out then to get in depending on the situation. With manifolded doubles you have access to more then a third of your gas (you'd only be deprived the amount lost in the time it took you to fix the problem) if you have any failure other then manifold or tank neck o-ring (which are the rarest failures) and very close to a third if you go for the isolator first and it does turn out to be one of those o-rings.

This is all academic, as proper gas management and teamwork make this problem irrelevant.

Ben

 

[Albion]

Albion. by only haveing the iso. cracked open the pressure at depth could close it. I saw this happen to a buddy at 60 feet in a single tank rig. He open his valve while gearing up to check the pressure but didn't open it up fully before the dive started. At 60 feet this diver started flipping out with an ooa. We just started the dive so I figured he was just practicing an OOA , untill I saw his arms and legs wildly flailing, You can tell when an OOA is for real.

also true, i've seen similar, someone had the tank vale half a turn from closed not from open. I didnt see them bolt for the surface of even know there was a problem (different buddy pair), but i looked up to see housed SLR camera floating down towards
me that her buddy had let go of as he went after her (slowly). Pity they were from the same dive shop had to give camera back afterwards

 

[fdog]

No, I've not had a massive gas loss while diving doubles.

I will shut the isolator first, no matter how tempting a particular post may be.

I'll always take the sure thing...half of remaining gas...instead of a "good chance" of saving more than half.

All the best, James