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Rebreatherlab · 19th May 2008, 05:56

Hi Gill,

Just start with a lower Po2 and you will not have any spiking. I typically start with pure O2, go to 20 ft, check cell liniarity, flush down to 0,6 or so and then just bomb down. Usually this puts me at 1,2 when reaching 160 ft. As we are talking fast descents you really dont have to worry about the short exposure below set point.

If I do a deeper dive with a slow descent and feel it would be nice to stay closer to set point during the descent I simply close the needle and metabolise some of the O2 on the way. depending on gas selection, depth and descent time this can actually work quite good.

Andy

Quote: (Originally Posted by Gill Envy)

hey Tyler, I've only done a few deepish dives in a range that i'd expect air dill not to drop my po2 adequately. Certainly going deeper than 200 will require hypoxic dill and trimix. Getting all the added certifcation may turn out to be of limited value to me though since the places i'd like to do long deep dives are on reefs that are so remote that getting anything other than compressed o2 and air is problematic... but that's really a subject for another post.

What attracts me to the needle valve on the Pelatian is that it sounds like a great way to tweek the o2 flow to match changing needs. Rapid descents were just one area I would find this convenient. I have my IP set to deliver just under my metabolic rate so that I hardly have to inject at all while at a constant depth, the downside to that is that it rises above 1.3 when i'm descending quickly even with adding dilluent. While that only happens for a short time, and i'm told many folks with eCCR's experience this as well, it would still be nice to have more control of... and then there is the advantage of removing the whole depth limit thing altogether.

Mod 2 and 3 are likely an inevitability and I guess i'm mostly looking down the road, for to the configuration in mCCR I will likely want so that I can make most of the big changes now and grow accustom to them before adding all the other additional complexity of multiple gas mixes and so on.

g

19th May 2008, 05:56	#20 (permalink)
Rebreatherlab Rebreatherlab Rep Current Rebreather/s: Pelagian Other Rebreather/s: Not Bought Yet Classic Kiss Pelagian Join Date: Sep 2005 Location: Thailand Posts: 203	Re: Tried the Pelagian.... Hi Gill, Just start with a lower Po2 and you will not have any spiking. I typically start with pure O2, go to 20 ft, check cell liniarity, flush down to 0,6 or so and then just bomb down. Usually this puts me at 1,2 when reaching 160 ft. As we are talking fast descents you really dont have to worry about the short exposure below set point. If I do a deeper dive with a slow descent and feel it would be nice to stay closer to set point during the descent I simply close the needle and metabolise some of the O2 on the way. depending on gas selection, depth and descent time this can actually work quite good. Andy Quote: (Originally Posted by Gill Envy) hey Tyler, I've only done a few deepish dives in a range that i'd expect air dill not to drop my po2 adequately. Certainly going deeper than 200 will require hypoxic dill and trimix. Getting all the added certifcation may turn out to be of limited value to me though since the places i'd like to do long deep dives are on reefs that are so remote that getting anything other than compressed o2 and air is problematic... but that's really a subject for another post. What attracts me to the needle valve on the Pelatian is that it sounds like a great way to tweek the o2 flow to match changing needs. Rapid descents were just one area I would find this convenient. I have my IP set to deliver just under my metabolic rate so that I hardly have to inject at all while at a constant depth, the downside to that is that it rises above 1.3 when i'm descending quickly even with adding dilluent. While that only happens for a short time, and i'm told many folks with eCCR's experience this as well, it would still be nice to have more control of... and then there is the advantage of removing the whole depth limit thing altogether. Mod 2 and 3 are likely an inevitability and I guess i'm mostly looking down the road, for to the configuration in mCCR I will likely want so that I can make most of the big changes now and grow accustom to them before adding all the other additional complexity of multiple gas mixes and so on. g __________________ www.rebreatherlab.com
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