triox vs. trimix?

[milldog]

Originally Posted by Brian of Aquanauts

“An open mind leaves a chance for someone to drop a worthwhile thought in it”

“An open mind lets the interesting stuff drop out the back"

Graham

[GLOC]

Here's is one for those who dive with a lost deco plan that Si/Weazlez posted. How many people limit their bottom time based on their lost deco plan?

I know that when I had a AN&DP ticket and we were up in Scapa, that is how we worked out the actual bottom time for the main dive. This would have entailed losing a (pretty good) buddy and the deco gas but at least we knew we were going to surface okay.

Not meant to be a ruck, but if you are going to work out a lost deco plan, surely you should limit your BT to make sure you can do it on BG.

[Howard Payne]

Go and get a Meg off Chiz and get yer arse back in the water - YD's got quite enough armchair experts already

[big_si]

Originally Posted by GLOC

Here's is one for those who dive with a lost deco plan that Si/Weazlez posted. How many people limit their bottom time based on their lost deco plan?

I know that when I had a AN&DP ticket and we were up in Scapa, that is how we worked out the actual bottom time for the main dive. This would have entailed losing a (pretty good) buddy and the deco gas but at least we knew we were going to surface okay.

Not meant to be a ruck, but if you are going to work out a lost deco plan, surely you should limit your BT to make sure you can do it on BG.

Yep, that's exactly how I have V-planner set up... Gives a warning if more than 2/3 of back gas is used or more than 1/2 deco gas. Don't plan for any bottom time more than that.

[milldog]

Originally Posted by Howard Payne

Go and get a Meg off Chiz and get yer arse back in the water - YD's got quite enough armchair experets already

Sentinel mmmmmmmmmmm

sofa actually i can lie down as well

G

Just for measure lost deco gas .................................................. .find other diver on deco and mug them

[Steve S]

Originally Posted by Brian of Aquanauts

having decided that i'm totally useless as a diver and really ought to go back to diving in 20m of water until I can get my basic dive skills back in order, i'd now have to suddenly get my shit together and get myself out of that real idiotic position. Although if i were that bad a diver i doubt I'd have this skill either.

these are the choices:

Fix the rig so it's no longer "lost"
double all the stops on back gas and
send up an SMB with note attached for one of the support divers or other teams to bring spare gas down to me at 6m
Complete all stops (doubled) to 6m, do what I could at 6. Get out and keep monitoring for a sign of a bend. At least the chance of a CNS bend is low as the fast tissues should all be clear. Take ibuprofen, rest and breathe O2.

However your single deco gas loss isn't really so bad, as most of gas diving that I'm doing involves 2 or 3 deco gases, so I have lots of trained strategies that work using the reserve deco gases that I carry in the other bottles.

Our single deco gas to 45m example is actually possible to deco out on backgas quite easily by doubling stops, and reducing the conservatism that we planned in with our 30/85 gradient factors. Combine this with the above choices and you have lots of ways out of the problem if you can keep your wits about you.

Cheers for that mate, Juniors post that I quoted earlier, gave the impression that GUE trained divers couldn't become separated as others can and that got me wondering if that remote possibility was ever considered in DIR/GUE gas planning?

Thanks again.

Safe diving,
Steve

[Howard Payne]

Nope we're stuck to each other like Gary Glitter to a Ladyboy

[stevechesh]

Originally Posted by GLOC

. . . . . if you are going to work out a lost deco plan, surely you should limit your BT to make sure you can do it on BG.

Just run the 21/35 at 40 metres for 6 minutes through my 'puter. I've got lots of big numbers that look quite scary.....Thank god i dive air and can't see them!

A good analogy for me is: "There's too much time left at the end of the gas", a bit like " Too much month left at the end of the money"!

[weazelz]

Originally Posted by big_si

Yep, that's exactly how I have V-planner set up... Gives a warning if more than 2/3 of back gas is used or more than 1/2 deco gas. Don't plan for any bottom time more than that.

ditto

[IanDennis]

Originally Posted by Brian of Aquanauts

these are the choices:

Fix the rig so it's no longer "lost"
double all the stops on back gas and
send up an SMB with note attached for one of the support divers or other teams to bring spare gas down to me at 6m
Complete all stops (doubled) to 6m, do what I could at 6. Get out and keep monitoring for a sign of a bend. At least the chance of a CNS bend is low as the fast tissues should all be clear. Take ibuprofen, rest and breathe O2.

Our single deco gas to 45m example is actually possible to deco out on backgas quite easily by doubling stops, and reducing the conservatism that we planned in with our 30/85 gradient factors. Combine this with the above choices and you have lots of ways out of the problem if you can keep your wits about you.

All possible choices and you should have sufficient backgas remaining - if your monitoring gas and using 1/3rds. Once it all starts to go wrong and your by yourself then irrespective of agency the solutions are all pretty much the same.

With team diving (assuming you actually stay together) there are more options available and more gas