why NOT using OC/DSV?

decoweenie · 21st January 2006, 08:33

Quote: (Originally Posted by silent running)

Other than weight and bulk...

There is really no additional weight u/w. Once the BOV is out of my mouth, it immediately try to float up.

Yes, the KISS BOV is larger than DSV, but could you really classify it as "bulk" as in bulky ? i don't believe so. But I agree that there are some BOV quite bulky. However, they incorporate larger 2d stage to better breathing.

Quote:

is there any downside to having a full blown high performance 2nd stage on your BOV and using it for the full length of a bailout, instead of going to an off board reg?

Just is just IMHO...

I carry OC-bail-out stages not just for me, but also for my buddies or anyone else who might need it.

If I was to plumb that stage into my "hi-performance" BOV, there is no need for the separate and independent 2nd stage on the OC-bail-out stage. Then how do I share with someone else ?

You might argue why take the stage 2nd stage off, then why go thru theweight and bulk compromise of having to use a "hi-performance" BOV when you could simply make the switch in 5 seconds ?

Quote:

...take the mouth pc out of your mouth and let the hose float around free over your head, which could be an entanglement hazard in a confined space... -Andy

You don't have to keep the Rebreather hose assembly float above your head in such scenario, you just keep it under your chin like the back-up reg in the Hogarthian set-up. That's how I keep mine when exercising bail-out.

silent running · 21st January 2006, 09:50

Quote: (Originally Posted by decoweenie)

There is really no additional weight u/w. Once the BOV is out of my mouth, it immediately try to float up.

Yes, the KISS BOV is larger than DSV, but could you really classify it as "bulk" as in bulky ? i don't believe so. But I agree that there are some BOV quite bulky. However, they incorporate larger 2d stage to better breathing.

Just is just IMHO...

I carry OC-bail-out stages not just for me, but also for my buddies or anyone else who might need it.

If I was to plumb that stage into my "hi-performance" BOV, there is no need for the separate and independent 2nd stage on the OC-bail-out stage. Then how do I share with someone else ?

You might argue why take the stage 2nd stage off, then why go thru theweight and bulk compromise of having to use a "hi-performance" BOV when you could simply make the switch in 5 seconds ?

You don't have to keep the Rebreather hose assembly float above your head in such scenario, you just keep it under your chin like the back-up reg in the Hogarthian set-up. That's how I keep mine when exercising bail-out.

Phi, just to be clear, I was refering to the extra bulk and weight of a BOV which allows for the use of a stock high performance 2nd stage while it's in your mouth, like the Divematics, as opposed to the KISS BOV.
Thanks again for the input. -Andy

decoweenie · 21st January 2006, 10:41

Quote: (Originally Posted by silent running)

...I was refering to the extra bulk and weight of a BOV which allows for the use of a stock high performance 2nd stage while it's in your mouth, like the Divematics, as opposed to the KISS BOV...

High-performance 2nd stage doesn't mean bulk as well.

I bought the Nemotech BOV from Joe Radomski. Eventhough it has the SP 2nd stage components for the OC portion, it is about the same size as the KISS BOV.

nskdrs · 21st January 2006, 11:36

Quote:

Quote: (Originally Posted by Mr. Greekbird)

what do you mean exactly?

paul

Uh, caught me there.

One may want to ease up on me as I run out of english fast.

Just trying to remember some basics as people seem to have doubts about likely tiny timeframe to react on a CO2 windup at depth.
I could well make sense to keep this simple causal contiguity in mind to remember the increasing risk (on Rebreather beyond scrubber-breakthrough ) in mind when diving deep( say past 60m ).

RMV jumps high as one runs into workload ( say from 20lpm easy up to 100+ lpm ), be it on land or at given depth.
Maximum RMV through a life supportsystem, be it Rebreather or OC is restricted due to WOB of the device and WOB in total being depth-dependant due to increasing gas-density.

Diver starts to overbreathe as the actual maximum RMV being possible through the respiratory device at given depth is excelled by gas-exchange requested by divers body.
Even jumping up to 40/50 lpm might be enough to overbreathe some setups at depth and have the CO2-spiral initiated.

Doing the math might show how disturbingly low the maximum RMV's possible at certain depths and gases are. High He-contents / Heliox sure is a big helper here.

The deadly spiral is turning, CO2 is building up fast as maximum possible gas exchange-rates can't cope with divers needs.
Lets keep possible masking effects ( may well be connected to high PO2 ) in mind at this point, as some distraction might occur.

Beyond a certain depth( construction related ) the maximimum RMV possible on Rebreather can be excelled by the maximum gas-exchange which can be achieved on OC,
again, this will be device-dependant for Rebreather and OC.
Just a guess, may it well be something like 100m on a widely spread Rebreather with low WOB, OTS-CL design, 10/50 DIL.

So, switching to a goooood BOV eventually will instantly help in terms of delivering enough gas-exchange to cope with RMV on demand.

Just need "tiny" bit more OC-gas.

IMHO also a BOV with flaws might help as it is good for some ( wellnamed ) "sanity"-breaths, then swapping to better regs.

Just another reminding thought helping just me to justify a BOV.

regards,
hoffi

rogeringebo · 3rd February 2006, 20:54

Who has mounted a DSV/OC to the Meg and how was the result? (has probably been up on the forum 10 times but Im a

here...)
Rodge

View Poll Results: I use
DSV	47	47.00%
OC / DSV	50	50.00%
FFM OC / DSV	6	6.00%
Multiple Choice Poll. Voters: 100. You may not vote on this poll

21st January 2006, 08:33	#81 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Re: why NOT using OC/DSV? Quote: (Originally Posted by silent running) Other than weight and bulk... There is really no additional weight u/w. Once the BOV is out of my mouth, it immediately try to float up. Yes, the KISS BOV is larger than DSV, but could you really classify it as "bulk" as in bulky ? i don't believe so. But I agree that there are some BOV quite bulky. However, they incorporate larger 2d stage to better breathing. Quote: is there any downside to having a full blown high performance 2nd stage on your BOV and using it for the full length of a bailout, instead of going to an off board reg? Just is just IMHO... I carry OC-bail-out stages not just for me, but also for my buddies or anyone else who might need it. If I was to plumb that stage into my "hi-performance" BOV, there is no need for the separate and independent 2nd stage on the OC-bail-out stage. Then how do I share with someone else ? You might argue why take the stage 2nd stage off, then why go thru theweight and bulk compromise of having to use a "hi-performance" BOV when you could simply make the switch in 5 seconds ? Quote: ...take the mouth pc out of your mouth and let the hose float around free over your head, which could be an entanglement hazard in a confined space... -Andy You don't have to keep the Rebreather hose assembly float above your head in such scenario, you just keep it under your chin like the back-up reg in the Hogarthian set-up. That's how I keep mine when exercising bail-out. __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
(Offline)

21st January 2006, 09:50	#82 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,836	Re: why NOT using OC/DSV? Quote: (Originally Posted by decoweenie) There is really no additional weight u/w. Once the BOV is out of my mouth, it immediately try to float up. Yes, the KISS BOV is larger than DSV, but could you really classify it as "bulk" as in bulky ? i don't believe so. But I agree that there are some BOV quite bulky. However, they incorporate larger 2d stage to better breathing. Just is just IMHO... I carry OC-bail-out stages not just for me, but also for my buddies or anyone else who might need it. If I was to plumb that stage into my "hi-performance" BOV, there is no need for the separate and independent 2nd stage on the OC-bail-out stage. Then how do I share with someone else ? You might argue why take the stage 2nd stage off, then why go thru theweight and bulk compromise of having to use a "hi-performance" BOV when you could simply make the switch in 5 seconds ? You don't have to keep the Rebreather hose assembly float above your head in such scenario, you just keep it under your chin like the back-up reg in the Hogarthian set-up. That's how I keep mine when exercising bail-out. Phi, just to be clear, I was refering to the extra bulk and weight of a BOV which allows for the use of a stock high performance 2nd stage while it's in your mouth, like the Divematics, as opposed to the KISS BOV. Thanks again for the input. -Andy
(Offline)

21st January 2006, 10:41	#83 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Re: why NOT using OC/DSV? Quote: (Originally Posted by silent running) ...I was refering to the extra bulk and weight of a BOV which allows for the use of a stock high performance 2nd stage while it's in your mouth, like the Divematics, as opposed to the KISS BOV... High-performance 2nd stage doesn't mean bulk as well. I bought the Nemotech BOV from Joe Radomski. Eventhough it has the SP 2nd stage components for the OC portion, it is about the same size as the KISS BOV. __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
(Offline)

21st January 2006, 11:36	#84 (permalink)
nskdrs New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Classic Kiss Not Bought Yet Join Date: Sep 2005 Location: germany Posts: 96	Re: why NOT using OC/DSV? Quote: Quote: (Originally Posted by Mr. Greekbird) what do you mean exactly? paul Uh, caught me there. One may want to ease up on me as I run out of english fast. Just trying to remember some basics as people seem to have doubts about likely tiny timeframe to react on a CO2 windup at depth. I could well make sense to keep this simple causal contiguity in mind to remember the increasing risk (on Rebreather beyond scrubber-breakthrough ) in mind when diving deep( say past 60m ). RMV jumps high as one runs into workload ( say from 20lpm easy up to 100+ lpm ), be it on land or at given depth. Maximum RMV through a life supportsystem, be it Rebreather or OC is restricted due to WOB of the device and WOB in total being depth-dependant due to increasing gas-density. Diver starts to overbreathe as the actual maximum RMV being possible through the respiratory device at given depth is excelled by gas-exchange requested by divers body. Even jumping up to 40/50 lpm might be enough to overbreathe some setups at depth and have the CO2-spiral initiated. Doing the math might show how disturbingly low the maximum RMV's possible at certain depths and gases are. High He-contents / Heliox sure is a big helper here. The deadly spiral is turning, CO2 is building up fast as maximum possible gas exchange-rates can't cope with divers needs. Lets keep possible masking effects ( may well be connected to high PO2 ) in mind at this point, as some distraction might occur. Beyond a certain depth( construction related ) the maximimum RMV possible on Rebreather can be excelled by the maximum gas-exchange which can be achieved on OC, again, this will be device-dependant for Rebreather and OC. Just a guess, may it well be something like 100m on a widely spread Rebreather with low WOB, OTS-CL design, 10/50 DIL. So, switching to a goooood BOV eventually will instantly help in terms of delivering enough gas-exchange to cope with RMV on demand. Just need "tiny" bit more OC-gas. IMHO also a BOV with flaws might help as it is good for some ( wellnamed ) "sanity"-breaths, then swapping to better regs. Just another reminding thought helping just me to justify a BOV. regards, hoffi
(Offline)

3rd February 2006, 20:54	#85 (permalink)
rogeringebo Custom Title Allowed! Current Rebreather/s: Pelagian Other Rebreather/s: Megalodon Classic Kiss Pelagian Join Date: Sep 2005 Location: Stockholm Sweden Posts: 700	Re: why NOT using OC/DSV? Who has mounted a DSV/OC to the Meg and how was the result? (has probably been up on the forum 10 times but Im a here...) Rodge
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