Backgas Reserve in a Stage Bottle?

[J1M1]

In addition to normal dive planning where I want to have sufficient gas to meet 1.5 times the planned back gas requirements and 1.2 times the planned deco gas requirements, you also need to ensure you have suffcient gas to do the whole dive on your backgas if the need arises.

I dont follow your thoughts. Are you saying that on a trimix dive you carry enough gas in your cylinders to make the whole dive including deco on the back mix? This would give you a bottom time at 250ft of like 3-4 minutes on say a 14/50 for back mix. To finish deco on a 20 minute dive to 250ft on backgas of say a 14/50 would require over ten hours of deco. ..Alot of people DO use 32-38% for deco on a dive like this. You can get on it earlier. I understand that this is not the preferred gas by most divers for deep dives with deco but it is also a good option, especially for deeper stops or in an emergency you could go to it deeper...JD

 

[Scuba_Steve]

blind leading the blind

Hmmm, not really sure of this, but if you mean that I wouldn't be capable of planning and executing this dive properly, this would be in err.

If not, my apologies.

The fact that I used to to some pretty stupid stuff, and have since gained the mindset that is required to do such dives, and have backed off a bit (a lot), speaks volumes of my Instructors, as far as I'm concerned. It takes brains to realize your real limits, not your ill conceived limits. It also didn't take much at all to realize that I've seen this type of situation way too often. It takes WAY MORE consideration than just "do I have enough gas"!!! Crap....that's the easy part! As I've said, any D/Knob can do a dive, but is it as safe and as well thought out and trained for, as it should be?

And for Tony, congrats buddy! By you last post, I can see you're taking all this with a positive spin and not a negative one. It takes a person of considerable character to thank those who have been quite negative on your plan.

Gotta run gents.

Steve

 

[MikeFerrara]

In addition to normal dive planning where I want to have sufficient gas to meet 1.5 times the planned back gas requirements and 1.2 times the planned deco gas requirements, you also need to ensure you have suffcient gas to do the whole dive on your backgas if the need arises.

Not exactly. If we are diving with only one decompression gas we make sure that we can finish the dive on back gas if it's lost. However, on deeper/longer dives where we are using 2 decompression gasses, we make sure that we have enough gas to get by if we lose either decompression gas. In this case the loss of both would aften result in needing far more back gas than we could carry.

I also do not see the point in using Nitrox 36 for deco. You'd be better off with Nitrox 50 and if using two deco gases, I'd go with Nitrox 50 and Nitrox 80 or Nitrox 50 and 100% in that order of preference.

When we use 3 decompression gasses the third is 35%...36% would be ok too. The three would be O2, 50% and 35%. On occassion we have used 35% in place of 50% when only diving 2 decompression gasses but not often and it isn't my first choice.

 

[kramynot2000]

And for Tony, congrats buddy! By you last post, I can see you're taking all this with a positive spin and not a negative one. It takes a person of considerable character to thank those who have been quite negative on your plan.

Thanks and I do really listen to the opinions (of which there are many) although some opinions are given in a tone more harsh than others, but that's no big deal. We all know that people have been trained in a variety of ways with a variety of techniques, even within the same agency and so there is something to learn from what everyone has to say.

 

[msandler]

Hmmm, not really sure of this, but if you mean that I wouldn't be capable of planning and executing this dive properly, this would be in err.

If not, my apologies.

The fact that I used to to some pretty stupid stuff, and have since gained the mindset that is required to do such dives, and have backed off a bit (a lot), speaks volumes of my Instructors, as far as I'm concerned. It takes brains to realize your real limits, not your ill conceived limits. It also didn't take much at all to realize that I've seen this type of situation way too often. It takes WAY MORE consideration than just "do I have enough gas"!!! Crap....that's the easy part! As I've said, any D/Knob can do a dive, but is it as safe and as well thought out and trained for, as it should be?

And for Tony, congrats buddy! By you last post, I can see you're taking all this with a positive spin and not a negative one. It takes a person of considerable character to thank those who have been quite negative on your plan.

Gotta run gents.

Steve

Sorry Steve, for the confusion. I am in agreement with you. (I should have quoted nova...) I was referring to Nova instructing Kramy (blind leading the blind) Not you, your experience is evident in your post. That is why I quoted your comment to Nova.

For what its worth (now that I have alienated everyone) I also agree to tony's superior character.

 

[Scuba_Steve]

Thanks guys, it's great to see we can act civil with each other occassionally

I'm off for more training as we speak!

See y'all in a few.

 

[novadiver]

Sorry Steve, for the confusion. I am in agreement with you. (I should have quoted nova...) I was referring to Nova instructing Kramy (blind leading the blind) Not you, your experience is evident in your post. That is why I quoted your comment to Nova.

For what its worth (now that I have alienated everyone) I also agree to tony's superior character.

I was triing to talk this guy out of this dive also.But I know there is a place called forty fathams grotto that will teach you how to do this profile on air.

And for what it's worth, just because I throw the numbers through a planner , to try and help another diver, shouldn't put me in the BLIND DOORKNOB catigory. I may not be trimix, but I do have my deco cert.

 

[MontereyCADiver]

OK, this is an old saying that my flight instructor taught me:
"The superior pilot uses his superior judgement to avoid situations in which he has to demonstrate his superior skill."

I suppose the same could be said for us SCUBA divers -- Think about it.

Ciao, Jeff

 

[Eric__U]

Dont forget your snorkel