dennisgrimm
Registered
From the teaching that has been bestowed upon me by my LDS and instructors I now dive with my isolator closed and with 2 SPG's. The reasoning for this is that in the event of a catastrophic gas loss I would not lose all of my gas. The downside is a little more gas management and thinking. So here are my questions...
How many people out there think the same way? If not, why? I get the impression that most people dive with their isolator open. Is that the case?
If you dive with your isolator open (and presumably have one SPG) and have a gas loss then you have to reach back and close your isolator very quickly to prevent a total loss of breathing gas. I think that this would be very stressful (more so than having the isolator closed). If in this scenario you have now successfully shut down your isolator to preserve as much gas as possible and are now possibly breathing from the tank without the SPG how do you know how much gas you have? Obviously you would abort the dive, but I would be worried about having enough gas to complete my deco. I realize that you could shut down the free flowing tank and re-open the isolator, but what if you weren't quick enough (because you had to shut your isolator and then your leaking tank) and lost all the gas out of that tank. Would you still re-open the isolator? Also, wouldn't you worry a little about the unlikely event where you have a gas loss in a confined place where you couldn't reach your isolator (cave or wreck)?
I have been taught that by having the isolator closed and essentially diving independents you get all of the redundancy associated with doubles without the downsides of having a manifold. In the event of a gas loss I could switch regs (if necessary), calmly (because I know that the gas I am breathing is not at risk) reach back and shut down the offending tank, check to see if any gas remains in that tank, and open the isolator if there is sufficient gas to warrant it.
BTW: I did search this topic and found a great deal of interesting discussions about the benefits of independents VS manifold, but didn't come up with anything related to having the isolator open or closed. I apologize if this has already been beat to death, I am relatively new.
How many people out there think the same way? If not, why? I get the impression that most people dive with their isolator open. Is that the case?
If you dive with your isolator open (and presumably have one SPG) and have a gas loss then you have to reach back and close your isolator very quickly to prevent a total loss of breathing gas. I think that this would be very stressful (more so than having the isolator closed). If in this scenario you have now successfully shut down your isolator to preserve as much gas as possible and are now possibly breathing from the tank without the SPG how do you know how much gas you have? Obviously you would abort the dive, but I would be worried about having enough gas to complete my deco. I realize that you could shut down the free flowing tank and re-open the isolator, but what if you weren't quick enough (because you had to shut your isolator and then your leaking tank) and lost all the gas out of that tank. Would you still re-open the isolator? Also, wouldn't you worry a little about the unlikely event where you have a gas loss in a confined place where you couldn't reach your isolator (cave or wreck)?
I have been taught that by having the isolator closed and essentially diving independents you get all of the redundancy associated with doubles without the downsides of having a manifold. In the event of a gas loss I could switch regs (if necessary), calmly (because I know that the gas I am breathing is not at risk) reach back and shut down the offending tank, check to see if any gas remains in that tank, and open the isolator if there is sufficient gas to warrant it.
BTW: I did search this topic and found a great deal of interesting discussions about the benefits of independents VS manifold, but didn't come up with anything related to having the isolator open or closed. I apologize if this has already been beat to death, I am relatively new.