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Drmike · 4th May 2008, 12:47

Quote: (Originally Posted by Lancer4545)

I had an interesting discussion recently regarding gas consumption and deco time when diving on HeliOx as compared to diving with Trimix.

It came about when we were on our last deep wreck trip and the guys were working out our Helium consumption and then comparing that to what they expected the HeliOx divers would use.

I ran the profiles through my planning software and always came up with longer deco and run times compared to the mix we were on.

Our mix was 16/45 and the Heliox guys were going to use 10/90 for the same 75m dives.

I got a reply back the other day and nearly fell off my chair when I saw what these guys were diving.

<paste>

As promised (names withheld) did all the blending and they used hardly any He at all- those blokes really know what they're on.

they boosted a little O2 on top of a full cylinder of He and then topped off Dil tanks as required. they were diving 40-60mins bottom, 200 mins total run max

We were doing similar bottom times to these and were coming up with total run time nearly an hour longer. Plug their mix in and the end result is over another hour deco longer.

Is there something I am missing here or is someone blazing a new (and dangerous) trail?

Regards,

Lance

ADDED Please, Please......Lets not turn this into a bashing place and lets keep it on subject!!

My approach to deco planning is: in areas we know very little, its best to be conservative.

Ergo, deep and bounce dives, Heliox dives (or near as damn it) I do very conservative deco. Who cares if I have to stay in the water a few hours longer than may be necessary- when you look at the risk V reward of a bad bend a few hours is not at all significant in my opinion.

I suspect habitual chasing of shortest deco times will greatly increase risk of injury eventually where as carrying out conservative deco times just means some bastards more likely to have ate all your damn food! (be careful when using hobbits as support divers!]

4th May 2008, 12:47	#25 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: Trimix Versus HeliOx and Deco time Quote: (Originally Posted by Lancer4545) I had an interesting discussion recently regarding gas consumption and deco time when diving on HeliOx as compared to diving with Trimix. It came about when we were on our last deep wreck trip and the guys were working out our Helium consumption and then comparing that to what they expected the HeliOx divers would use. I ran the profiles through my planning software and always came up with longer deco and run times compared to the mix we were on. Our mix was 16/45 and the Heliox guys were going to use 10/90 for the same 75m dives. I got a reply back the other day and nearly fell off my chair when I saw what these guys were diving. <paste> As promised (names withheld) did all the blending and they used hardly any He at all- those blokes really know what they're on. they boosted a little O2 on top of a full cylinder of He and then topped off Dil tanks as required. they were diving 40-60mins bottom, 200 mins total run max We were doing similar bottom times to these and were coming up with total run time nearly an hour longer. Plug their mix in and the end result is over another hour deco longer. Is there something I am missing here or is someone blazing a new (and dangerous) trail? Regards, Lance ADDED Please, Please......Lets not turn this into a bashing place and lets keep it on subject!! My approach to deco planning is: in areas we know very little, its best to be conservative. Ergo, deep and bounce dives, Heliox dives (or near as damn it) I do very conservative deco. Who cares if I have to stay in the water a few hours longer than may be necessary- when you look at the risk V reward of a bad bend a few hours is not at all significant in my opinion. I suspect habitual chasing of shortest deco times will greatly increase risk of injury eventually where as carrying out conservative deco times just means some bastards more likely to have ate all your damn food! (be careful when using hobbits as support divers!] __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 4th May 2008 at 12:55.
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