mCCR and zero viz exit

Brad_Horn · 31st March 2008, 10:59

Matt,

Have you seen the MK16 series with the HUD attached to the mask?

With something like the Shearwater HUD, you can't loose sight of your PPo2!

Regards
Brad

graham_hk · 31st March 2008, 11:28

I fail to see how this is unique to mCCR - personally I wouldn't want electronics managing PO2 when I couldn't monitor it. Semi closed would be what I would choose to do.

Graham

PCDiver · 31st March 2008, 11:52

Quote: (Originally Posted by graham_hk)

I fail to see how this is unique to mCCR - personally I wouldn't want electronics managing PO2 when I couldn't monitor it. Semi closed would be what I would choose to do.

Graham

I don't completely agree. Based on the sound of the solenoid and the volume changes in the loop (no changes if you stay at the same depth), you should be able to determine whether your controller is working or not. On the Inspo/Evo the buzzer will alert you for life critical situations. If you don't hear the solenoid for a while, then it's time to bailout because the solenoid firing is the only way to find out whether the controller is working or not without a visual reference.

**wedivebc** · 31st March 2008, 12:44

The Carleton RBs that the Canadian Navy uses places a LED inside the mask for a HUD. Probably would be a useful idea for a MCCR cave diver too.

jkaterenchuk · 31st March 2008, 12:59

Quote: (Originally Posted by mattmexico)

yo

My point here is not so much to point fingers or make a big fuzz, it just got me thinking about mCCR in zero viz situations, especially when under high stress and work load.

Just wanted to let the forum know about this potential issue that was prevented and how to overcome it in future procedure.

greetings
Matt

Matt

As an experienced CCR Cave instructor and diver I would be interested in knowing what you think the correct procedures should be for this situation? Additionally, is a skill drill to practise included in the CCR Cave course requirements with any agency?

John

Meng_Tze · 31st March 2008, 13:17

Quote: (Originally Posted by caverkevin)

..
I really do not like the idea of diving a rebreather without a HUD to watch my PPO2. My Shearwater HUD gives me all sort of warm fuzzy feelings while diving my KISS.

Cheers!!

Kevin

I agree Kevin. A HUD, especially in a cave, is one of THE most indispensable pieces of equipment you can have on a Rebreather. Short of sticking your head physically in the mud, a HUD can be seen in all sorts of low/no vis situations.

Ben Field · 31st March 2008, 13:35

Quote: (Originally Posted by wedivebc)

The Carleton RBs that the Canadian Navy uses places a LED inside the mask for a HUD. Probably would be a useful idea for a MCCR cave diver too.

This thread has made me think that perhaps I should mount my SW HUD to my mask rather than my BOV/DSV.
I can see it would be "another" thing to remember when dekitting, maybe harder to focus on?

I'm thinking make up a clear mount on the outside of my mask lense and simple unclip and move the HUD once I've donned the unit, cable can still run around the breathing hose just leave abit more slack...

Might be worth trying, I'm diving the UK south coast this weekend, sure to be fairly crappy

Mark Chase · 31st March 2008, 14:00

Errrrrr ? was this me

If so i don't mind you saying so. Incidents should be shared and discussed and not hidden in a closet.

Its exactly what happened to me on the cave course. Patric taped me on the head I open my eyes, checked my unit and was on 0.20. A real eyeopener in terms of being too focused on the drill and not enough on the dive.

Ironically we had briefly discussed this before the incident and I said if I couldn't asses my PP02 id go OC or SCR till I could. And that exactly what I would do on a "normal dive".

HOWEVER, After this incident I made another decision: We were air dill and max 14m so i decided on a plan B which was to count then blindly inject.
Owing to the fact we were on a course and I needed my bailout tin for the next dive (no refills avbl) I felt it necessary to attempt the blind injection option.

I practiced blind injection with the HUDD turned away so I couldent see it and checking on my hand set. It seemed OK and I did this on the blind exits after the event. I felt the risk of 02 tox at 14m and getting shallower, was minimal compared to the risk of going hypoxic.

If i was exiting from a depth where blind 02 injection carried significant risk of tox id go SCR or OC. I carry the bailout and ill use it. Id expect to get to an area of improved viz and be able to go back on loop.

More importantly the only way i could fail to see my HUD was to have my eyes closed. The viz would have to be truly appalling for you to not see the HUD.

Ignore the date I hadent re set it after putting a new battery in.

ATB

Mark

**wedivebc** · 31st March 2008, 14:13

I am wondering if for Mexican cave diving especially a richer dil (40% or so) would not help this issue.

Paul Evans · 31st March 2008, 14:17

Been reading this thread with great interest.

Surely its simple. If you can't see you handset or a hud you don't know you P02. Get off the loop, get into better vis, go back on the loop. You are just going to get more stressed out not being able to see what you Po2 is!!!!

Very Very few fatalities are caused by divers running out of a breathable gas.
As has been said, the gas is there OC, use it.

31st March 2008, 10:59	#11 (permalink)
Brad_Horn New Member Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic MK 15.X Home Build Join Date: Mar 2005 Location: Australia Posts: 52	Re: mCCR and zero viz exit Matt, Have you seen the MK16 series with the HUD attached to the mask? With something like the Shearwater HUD, you can't loose sight of your PPo2! Regards Brad
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31st March 2008, 11:28	#12 (permalink)
graham_hk New Member Current Rebreather/s: RB80 / Clone Other Rebreather/s: Inspiration Classic Classic Kiss MK 15.X RB80 / Clone Join Date: Nov 2005 Location: Philippines Posts: 76	Re: mCCR and zero viz exit I fail to see how this is unique to mCCR - personally I wouldn't want electronics managing PO2 when I couldn't monitor it. Semi closed would be what I would choose to do. Graham
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31st March 2008, 11:52	#13 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 879	Re: mCCR and zero viz exit Quote: (Originally Posted by graham_hk) I fail to see how this is unique to mCCR - personally I wouldn't want electronics managing PO2 when I couldn't monitor it. Semi closed would be what I would choose to do. Graham I don't completely agree. Based on the sound of the solenoid and the volume changes in the loop (no changes if you stay at the same depth), you should be able to determine whether your controller is working or not. On the Inspo/Evo the buzzer will alert you for life critical situations. If you don't hear the solenoid for a while, then it's time to bailout because the solenoid firing is the only way to find out whether the controller is working or not without a visual reference. __________________ >>>>> www.submergeproductions.com dedicated to promoting technical diving >>>>> Check out our dive show video interviews at http://www.submergeproductions.com/A...nterviews.aspx >>>>> Wreck dive videos http://www.submergeproductions.com/A...omthedeep.aspx
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31st March 2008, 12:44	#14 (permalink)
wedivebc FIGJAM Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,337	Re: mCCR and zero viz exit The Carleton RBs that the Canadian Navy uses places a LED inside the mask for a HUD. Probably would be a useful idea for a MCCR cave diver too. __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
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31st March 2008, 12:59	#15 (permalink)
jkaterenchuk . Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Other Rebreather/s: Join Date: May 2006 Location: Lititz, PA Posts: 558	Re: mCCR and zero viz exit Quote: (Originally Posted by mattmexico) yo My point here is not so much to point fingers or make a big fuzz, it just got me thinking about mCCR in zero viz situations, especially when under high stress and work load. Just wanted to let the forum know about this potential issue that was prevented and how to overcome it in future procedure. greetings Matt Matt As an experienced CCR Cave instructor and diver I would be interested in knowing what you think the correct procedures should be for this situation? Additionally, is a skill drill to practise included in the CCR Cave course requirements with any agency? John
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31st March 2008, 13:17	#16 (permalink)
Meng_Tze 246 Bubbleless Cove Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2007 Location: FL, USA Posts: 101	Re: mCCR and zero viz exit Quote: (Originally Posted by caverkevin) .. I really do not like the idea of diving a rebreather without a HUD to watch my PPO2. My Shearwater HUD gives me all sort of warm fuzzy feelings while diving my KISS. Cheers!! Kevin I agree Kevin. A HUD, especially in a cave, is one of THE most indispensable pieces of equipment you can have on a Rebreather. Short of sticking your head physically in the mud, a HUD can be seen in all sorts of low/no vis situations. __________________ Homo Bonae Voluntatis
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31st March 2008, 13:35	#17 (permalink)
Ben Field CK+Shearwater Current Rebreather/s: Classic Kiss Other Rebreather/s: Sport Kiss Join Date: Aug 2005 Location: London, England Posts: 1,442	Re: mCCR and zero viz exit Quote: (Originally Posted by wedivebc) The Carleton RBs that the Canadian Navy uses places a LED inside the mask for a HUD. Probably would be a useful idea for a MCCR cave diver too. This thread has made me think that perhaps I should mount my SW HUD to my mask rather than my BOV/DSV. I can see it would be "another" thing to remember when dekitting, maybe harder to focus on? I'm thinking make up a clear mount on the outside of my mask lense and simple unclip and move the HUD once I've donned the unit, cable can still run around the breathing hose just leave abit more slack... Might be worth trying, I'm diving the UK south coast this weekend, sure to be fairly crappy __________________ www.hugsac.org.uk Beware Fridge Suck
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31st March 2008, 14:00	#18 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Jan 2005 Location: Kent Posts: 2,410	Re: mCCR and zero viz exit Errrrrr ? was this me If so i don't mind you saying so. Incidents should be shared and discussed and not hidden in a closet. Its exactly what happened to me on the cave course. Patric taped me on the head I open my eyes, checked my unit and was on 0.20. A real eyeopener in terms of being too focused on the drill and not enough on the dive. Ironically we had briefly discussed this before the incident and I said if I couldn't asses my PP02 id go OC or SCR till I could. And that exactly what I would do on a "normal dive". HOWEVER, After this incident I made another decision: We were air dill and max 14m so i decided on a plan B which was to count then blindly inject. Owing to the fact we were on a course and I needed my bailout tin for the next dive (no refills avbl) I felt it necessary to attempt the blind injection option. I practiced blind injection with the HUDD turned away so I couldent see it and checking on my hand set. It seemed OK and I did this on the blind exits after the event. I felt the risk of 02 tox at 14m and getting shallower, was minimal compared to the risk of going hypoxic. If i was exiting from a depth where blind 02 injection carried significant risk of tox id go SCR or OC. I carry the bailout and ill use it. Id expect to get to an area of improved viz and be able to go back on loop. More importantly the only way i could fail to see my HUD was to have my eyes closed. The viz would have to be truly appalling for you to not see the HUD. Ignore the date I hadent re set it after putting a new battery in. ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System Last edited by Mark Chase : 31st March 2008 at 14:07.
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31st March 2008, 14:13	#19 (permalink)
wedivebc FIGJAM Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,337	Re: mCCR and zero viz exit I am wondering if for Mexican cave diving especially a richer dil (40% or so) would not help this issue. __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
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31st March 2008, 14:17	#20 (permalink)
Paul Evans Freedom is the Key. Current Rebreather/s: Megalodon Other Rebreather/s: Megalodon Join Date: Oct 2006 Location: London Posts: 129	Re: mCCR and zero viz exit Been reading this thread with great interest. Surely its simple. If you can't see you handset or a hud you don't know you P02. Get off the loop, get into better vis, go back on the loop. You are just going to get more stressed out not being able to see what you Po2 is!!!! Very Very few fatalities are caused by divers running out of a breathable gas. As has been said, the gas is there OC, use it. __________________ "Freedom is what you do with what's been done to you." Jean-Paul Sartre "Any time anyone says, 'there is only one right way to do this' your bullshit meter should be pegged. Its a presumptive statement, made by a person who fears being proved wrong." Bill Gavin.
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