Accident in Finland

[Uwe Sieg]

Hey Michael

Quick question: When you teach CCR in-water dive checks does this also include a check of both SPG's?

This will indicate very quickly if either dil or O2 cylinders are closed.

 

[Michael Thornton]

Uwe Sieg,
To be honest I have not required this while in the water but that does not mean it is not a good idea.

As part of the drill I take several breaths off the BOV, As well as check all MAVs etc and wing inflation. In theory this would drain the hoses on the dill side if the tank were turned off. To be more thorough this should also be when you check your SPGs so that you will actually see the SPG drop as the low pressure hoses are drained if the tank were to be turned off.

 

[Mark Chase]

Running 100% O2 6 meters and shallower (including surface) would not be enough if in error you have set 0.21 (i.e. MAN) as Setpoint for example on the Meg (or if the JJ controller fails to auto-switch to say 0.7 when the depth sensor kicks in).

Much better to remove alltogether unsafe Setpoints from any part of the Menu to reduce the risk of User Error.

Why not?


0.19 is life sustaining so if the units auto switch failed to operate the worst thing that would happen is you do the whole dive on 0.19 and rack a massive amount of deco.


If the unit failed to maintain 0.19 and you didnt notice, you would die. Just the same as if the unit failed to maintain 0.7 and you didnt notice


From experiance I can assure you that running the unit manualy on pure 02 on the boat / surface ensures your on well over 1.0bar by 6m

ATB

Mark

 

[Mark Chase]

Uwe Sieg,
To be honest I have not required this while in the water but that does not mean it is not a good idea.

As part of the drill I take several breaths off the BOV, As well as check all MAVs etc and wing inflation. In theory this would drain the hoses on the dill side if the tank were turned off. To be more thorough this should also be when you check your SPGs so that you will actually see the SPG drop as the low pressure hoses are drained if the tank were to be turned off.

By the coment on checkling wing inflate I am asuming yor severl breaths off the BOV is on the boat?

You cant do this with a hypoxic mix, you will pass out as hapened to a CCR diver in the south China sea a couple of years ago who was on 10/50.

I check wing inflate with a blip of the button and I check the bov/dill with the purge button and look at the SPG


ATB

Mark

 

[Uwe Sieg]

Well put Paul. With Mark's permission may I repeat what Mark Chase noted that made me add a BOV to my setup: (not exact quote) "...if you never have to use a BOV, which I hope you never have to do, that is great. However if you do get into a situation that you need one, it might save your life. So why on earth would you not buy one?" One of the exiting things about CCR's is the development aspect. Look at AP; in addition to their temperature stick they have now added a CO2 monitor as well. (Well done guys) I think that the addition of CO2 monitoring device should be standard on all RB's by now. I really, really miss such a monitoring device on my Hammerhead since it is the only anomaly that I cannot monitor which can kill me. Or look at the DSV of the Poseidon Explorer; BOV already build in; another item I think should be standard on any RB design (or possible additional purchase option).

 

[Michael Thornton]

By the coment on checkling wing inflate I am asuming yor severl breaths off the BOV is on the boat?

You cant do this with a hypoxic mix, you will pass out as hapened to a CCR diver in the south China sea a couple of years ago who was on 10/50.

I check wing inflate with a blip of the button and I check the bov/dill with the purge button and look at the SPG


ATB

Mark

Obviously you have to be careful with hypoxic mixes. However I also want to add that the only way to truly know if your regulator is working is to test it in the water.

 

[Sharkjaw]

Mark,

Lucky you found it.
Nowadays I am not going anywhere near using the solenoid, running both sides manually.
Solenoid for very low PO2 only.
No more spikes, stuck open etc.

 

[DSix36]

My .02 for Michael and anyone else. Way back in this post the checklist was mentioned because you did a repair and turned your tanks off while doing it and then reentered the water without turning the tanks back on. I have been using my own mantra as a carry over from my Drager Dolphin days. If the DSV goes in my mouth, then the oxygen tank gets turned on (at least verified to be open); if the DSV comes out of my mouth, the oxygen tank gets turned off. This has been working very well for me and might give others something to think about.

 

[plazma]

One Finnish rebreather diver died few months ago. He dived a Sentinell
http://translate.google.com/translate?sl=fi&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.sukeltaja.fi%2Fcontent%2Ffi%2F11501%2F9572%2F227%2F227.html

 

[matt]

Quick question: When you teach CCR in-water dive checks does this also include a check of both SPG's?

This will indicate very quickly if either dil or O2 cylinders are closed.

I'm not sure why CCR divers quit doing the checks that are done routinely on OC. When I put my rig on I follow the same pattern everytime - and this include pressing the O2 button and confirming that the O2 SPG is reading on. For the dil I do the same - but draw the gas through the ADV.

Seems some common-sense went out the window in some of these incidents.

Matt.

 

[marcolman]

Hallo,
every divers should do a predive check starting from the open water diver to the more tech diver, but.... no one do it or they do it very fast and not carfully, I think that predive checks can surely save your life.