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Irish Cave Diver in the making
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Discussion Starter · #1 ·
Hi

I was on a boat the other week with a RB diver and he asked the skipper to drop him as close to the shot as he could. He didn't want to surface swim as he was using 10/50 dil and said it tired him out too quickly on the surface.

Now, this confused me a bit as it was eCCR, surely the unit would pump in more O2 and wouldn't have him breathing pure 10/50? Or is there a factor to the quantity of Helium over Nitrogen being breathed to increase fatigue? Or is it his imagination?

Thanks
.
 

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Apprentice houseplant
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988 Posts
Weird, that!

Yeah, as you say, if he's on ECCR, that ought to bring the O2 content to maybe 70%, assuming his setpoint was 0.7 bar on the surface.

Perhaps he's just a bit fat and lazy? ;)
 

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Hi

I was on a boat the other week with a RB diver and he asked the skipper to drop him as close to the shot as he could. He didn't want to surface swim as he was using 10/50 dil and said it tired him out too quickly on the surface.

Now, this confused me a bit as it was eCCR, surely the unit would pump in more O2 and wouldn't have him breathing pure 10/50? Or is there a factor to the quantity of Helium over Nitrogen being breathed to increase fatigue? Or is it his imagination?

Thanks
.

Your right total bull shit, initial set point would be .7 so shed loads of O2.


Richard Green
 

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No longer open water diver
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i know there are issues with low O2 mixes on open circuit at the surface and in shallow water, but i understand that he should be breathing around 70% on the surface depending on his set-point?

would suggest he needs to do his swim-test again! :wink:

or he is spoofing to get dropped on the shot

or he is imagining it

or there is a fault with his CCR :eek:mg:
 

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So raise your hand if you think that was a Russian
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11,158 Posts
Have a look at this thread on RBW, I don't recall if Keith posted it here.

After reading Keith's (extremely frank) report, I don't think that being dropped near the shot is the safest option in this instance.

r
P
 

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Retired depth-junkie, just a holiday scooby now
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1,130 Posts
Hi

I was on a boat the other week with a RB diver and he asked the skipper to drop him as close to the shot as he could. He didn't want to surface swim as he was using 10/50 dil and said it tired him out too quickly on the surface.

Now, this confused me a bit as it was eCCR, surely the unit would pump in more O2 and wouldn't have him breathing pure 10/50? Or is there a factor to the quantity of Helium over Nitrogen being breathed to increase fatigue? Or is it his imagination?

Thanks
.
Imagination pure and simple.

The only way this would be a problem was if his elecs or 02 were turned off.

If the unit was switched on and the 02 also on as well, the unit would be holding low setpoint (0.70) which aquates to an 02 content of 70% at the surface or 43% 02 @6m.





ATB
Gareth
 
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Irish Cave Diver in the making
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Discussion Starter · #7 ·
Thanks Guys you helped settle my mind on this.

I am still learning about CCR, so for all I know there could have been an issue, but I had never heard of something like that before.

Personally I think the guy is a bit unfit from other things I have noticed in the past. And the sea was a bit choppy and the current was running so...
.
 

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Hi

I was on a boat the other week with a RB diver and he asked the skipper to drop him as close to the shot as he could. He didn't want to surface swim as he was using 10/50 dil and said it tired him out too quickly on the surface.

Now, this confused me a bit as it was eCCR, surely the unit would pump in more O2 and wouldn't have him breathing pure 10/50? Or is there a factor to the quantity of Helium over Nitrogen being breathed to increase fatigue? Or is it his imagination?

Thanks
.

He's talking bollocks. He would be breathing 70%

It would be very interesting if he forgot to switch his o2 on though :)

Alan
 

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Irish Cave Diver in the making
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3,241 Posts
Discussion Starter · #9 ·
It would be very interesting if he forgot to switch his o2 on though :)
He was pre-breathing on the boat and didn't fall over, so I guess it was turned on :)
.
 

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Heavily medicated, for your safety.
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1,754 Posts
Personally I think the guy is a bit unfit from other things I have noticed in the past.
Now I know it wasn't me coz I had an air dil*. So it must have been that fat barsteward Midnight.

*That and the fact I'm so fit and svelte
 

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Big green button , push it and you have all the o2 you could ever want .

The man cant dive a rebreather , he don’t know sh1T, :spliff:
 

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Retired depth-junkie, just a holiday scooby now
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Big green button , push it and you have all the o2 you could ever want .

The man cant dive a rebreather , he don’t know sh1T, :spliff:
That and he sounds like he knows feck all about gas diving, especialy on a unit:)







ATB
Gareth
 

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Nefarious Activist
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2,298 Posts
Interesting thread, 3 posters have fallen into the trap of assuming that because the unit they dive would be giving 70% that all would, Boris for example would hold 40% unless you had turned the setpoint on manually. The OP didn't state what unit this diver was on, we should all be mindful of making assumptions about how other units operate.

Ian
 

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Interesting thread, 3 posters have fallen into the trap of assuming that because the unit they dive would be giving 70% that all would, Boris for example would hold 40% unless you had turned the setpoint on manually. The OP didn't state what unit this diver was on, we should all be mindful of making assumptions about how other units operate.

Ian

Ian

Mindfull or not .4, .7 would not make you breathlesss swimming for a shot too many pies would though.


Cheers


Richard
 

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not if he had the pie eating upgrade to his boris only costs 4800 quid and allows you to store 4 fray bentos just above the scrubber dome :)

Would you like the .4 or .7 size upgrade ? that'll be £££££££££££££££V£3


Richard


Below is the upgrade shown being slipped into the scrubber dome
 

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Registered
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Interesting thread, 3 posters have fallen into the trap of assuming that because the unit they dive would be giving 70% that all would, Boris for example would hold 40% unless you had turned the setpoint on manually. The OP didn't state what unit this diver was on, we should all be mindful of making assumptions about how other units operate.

Ian
Ian
i still have the same answer

Big green button , push it and you have all the o2 you could ever want .

dont matter what box your on you can breath what ever mix you want, when you want ,


sorry still say the chap knows sh1t,
 

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A short fat well off crap cave diver. Likes wrecks
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15,343 Posts
Unless he was on a MCCR this dosent make sense. Even on a MCCR it shouldent be an issue. FIll rig with pure 02 and jump in.

ATB

Mark Chase
 

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Unless he was on a MCCR this dosent make sense. Even on a MCCR it shouldent be an issue. FIll rig with pure 02 and jump in.

ATB

Mark Chase

you said it m8,
 

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Retired depth-junkie, just a holiday scooby now
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1,130 Posts
Ian
i still have the same answer

Big green button , push it and you have all the o2 you could ever want .

dont matter what box your on you can breath what ever mix you want, when you want ,


sorry still say the chap knows sh1t,
:thumbsup:






ATB
Gareth
 
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