SHADOW-DIVER
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Can you fit a AGA mask with a rebreather? What are the Pros and Cons?
AGA mask with a rebreather?
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There are to many negatives to diving with a full face mask and a rebreather:
1) I have never seen anyone get a perfect confortable fit were some gas dosn't escape, this is a problem for a rebreather
2) your field of view is not any better, it worse
3) large area for c02 build up
4) your putting all your eggs in one basket (bailing out becomes more of a problem), i had to ditch an aga in 220' of water and trust me IT WAS NO FUN AT ALL.
What are the advantages??
1) A warm face???? this becomes a problem if you have to ditch it. When that cold water hits your face YOU WILL TAKE ON WATER AND CHoKE as I did.
2) Communications???? good hand signals will cure that problem or video, discuss what you have to and do the dive again
I can't think of one GOOD reason to subject yourself to more risk without an upside.
1) I have never seen anyone get a perfect confortable fit were some gas dosn't escape, this is a problem for a rebreather
2) your field of view is not any better, it worse
3) large area for c02 build up
4) your putting all your eggs in one basket (bailing out becomes more of a problem), i had to ditch an aga in 220' of water and trust me IT WAS NO FUN AT ALL.
What are the advantages??
1) A warm face???? this becomes a problem if you have to ditch it. When that cold water hits your face YOU WILL TAKE ON WATER AND CHoKE as I did.
2) Communications???? good hand signals will cure that problem or video, discuss what you have to and do the dive again
I can't think of one GOOD reason to subject yourself to more risk without an upside.
Canadian Navy divers using CUMA and CCD2 rebreather have full face masks. Not AGA though.SHADOW-DIVER:
My only hesitation would be in the event of a CO2 breakthrough getting on OC quickly might be a problem. As you probably know when CO2 rises the feeling of air starvation comes on quickly. If you bailout requires you to remove the mask before getting to OC gas you may have problems doing it in an emergency. If I had a FFM on my rebreather I would want my bailout to be integrated in my DSV like the KISS.
caveseeker7
Contributor
The AGA mask was for a long time the standard FFM in use with the military in combination with the MK16 and was part of Carleton's CCBA 2001 system.
When used with a CCR the gas path needs to changed as the warm, moist gas would fog the mask, the opposite effect that OC gas has. That leaves a rather space, the oral/nasal pocket, where CO2 will accumulate.
Divematics (link above) sells kits that allow you to convert the AGA for RB use and offer a DSV or BOV that will fit your rebreather. Obviously the BOV is a better way to go as you won't have to take the mask off to use bailout. They also build the Widolf FFM with the same BOV build onto it. BigJetDriver69 here on the board uses that combo with his Inspiration.
Dräger's Nova looks a lot like the AGA, but was designed for use with rebreathers and connectors are available for all their civilian and military units. If your rebreather has the same hose diameter as a Dräger unit you should be able to connect your hoses to one of their DSVs. I've seen Meg hoses mounted to a Dräger FGT DSV for example. The Nova also has two additional ports, one on each side, for OC bailout and comms.
I believe the best solution is the Kirby-Morgan M-48 Supermask.
It was designed for use with OC or RB and can either take a reg, DSV or BOV.
Furthermore there is a bite piece on the inside of the pod that allows you to keep it in your mouth as you would with your DSV. Almost the same dead space as with your stock unit and no CO2 buildup. If you let go of the bite piece you still have a reasonably small space as the pod is not an oral/nasal pocket.
Finally, the pod can be realeased and you can use any normal OC second stage.
No need to remove the mask at all. They are available through K-M or Oceanic dealers.
For me the AGA and M-48 work well.
The Scubapro is too wide and the Mantis too small.
The M-48's field of vision sucks, the AGA's is very good.
The Cressi Big Eyes is very good and the Dacor Bandit sucks ...
But again, with a mask designed for it that's not an issue.
If you dive with a buddy that means there is a considerably better chance of surving a gas hit or hypoxia incident. Especially when your mask is equiped with a BOV and bailout is just a valve turn away.
FFMs with their four to five straps have a much lesser chance of being knocked off your face by some incosiderate moron
Less jaw fatigue.
Use of comms. If you like 'em or not is a personal preference, but they can come in handy. There is a reason they are required for most PSD work, used by commercial and military divers, scientific and other professional divers.
You can actually communicate head to head without comms.
The face stays warm and isolated from contammination. Ripping it off in very cold water might indeed cause shock, but so does ripping your drysuit. Doesn't seem to stop many Northeast wreckers now, does it.
When used with a CCR the gas path needs to changed as the warm, moist gas would fog the mask, the opposite effect that OC gas has. That leaves a rather space, the oral/nasal pocket, where CO2 will accumulate.
Divematics (link above) sells kits that allow you to convert the AGA for RB use and offer a DSV or BOV that will fit your rebreather. Obviously the BOV is a better way to go as you won't have to take the mask off to use bailout. They also build the Widolf FFM with the same BOV build onto it. BigJetDriver69 here on the board uses that combo with his Inspiration.
Dräger's Nova looks a lot like the AGA, but was designed for use with rebreathers and connectors are available for all their civilian and military units. If your rebreather has the same hose diameter as a Dräger unit you should be able to connect your hoses to one of their DSVs. I've seen Meg hoses mounted to a Dräger FGT DSV for example. The Nova also has two additional ports, one on each side, for OC bailout and comms.
I believe the best solution is the Kirby-Morgan M-48 Supermask.
It was designed for use with OC or RB and can either take a reg, DSV or BOV.
Furthermore there is a bite piece on the inside of the pod that allows you to keep it in your mouth as you would with your DSV. Almost the same dead space as with your stock unit and no CO2 buildup. If you let go of the bite piece you still have a reasonably small space as the pod is not an oral/nasal pocket.
Finally, the pod can be realeased and you can use any normal OC second stage.
No need to remove the mask at all. They are available through K-M or Oceanic dealers.
If the mask fits correctly, there will be no leaks, like any other mask.jptrealty:
For me the AGA and M-48 work well.
The Scubapro is too wide and the Mantis too small.
Depends on the masks, both the FFM and the half mask you're comparing it too.
The M-48's field of vision sucks, the AGA's is very good.
The Cressi Big Eyes is very good and the Dacor Bandit sucks ...
As discussed above, that too depends on the mask you're using.
Bailout why? OC or CC? The Divator II second stage on the AGA is as good and reliable as second stage gets, and it is a mask designed for OC. If gas needs to be switched for any reason it's done by using a switchblock. When used with a RB, it should have a BOV, not a DSV.
But again, with a mask designed for it that's not an issue.
Water will not enter your lungs when you're incapacitated.
If you dive with a buddy that means there is a considerably better chance of surving a gas hit or hypoxia incident. Especially when your mask is equiped with a BOV and bailout is just a valve turn away.
FFMs with their four to five straps have a much lesser chance of being knocked off your face by some incosiderate moron
Less jaw fatigue.
Use of comms. If you like 'em or not is a personal preference, but they can come in handy. There is a reason they are required for most PSD work, used by commercial and military divers, scientific and other professional divers.
You can actually communicate head to head without comms.
The face stays warm and isolated from contammination. Ripping it off in very cold water might indeed cause shock, but so does ripping your drysuit. Doesn't seem to stop many Northeast wreckers now, does it.
DrMike
Contributor
jptrealty:
IYHO
Mine fits fine thanks and I know many others without fit issues - Not all normal scuba masks fit either
True for some but not with all. To me this is a very small price to pay for the benefits
Not true if the mask is designed for RB use.
Not true if you use a BOV its easier than normal or a KM48 with its removable pod then bail out is no different.
I had to bail at 100m (330') and all it took was a turn of a lever then when needed the plug in of each of the three deco gasses at the right time using QCs. Never came off the mask, never lost vision, it was stress free and easy.
Er, its not possible to die through drowning?? Fairly important one I would have thought and certainly outweighs the only real disadvantage of slightly reduced vision (in the case of the KM48)
http://www.scubaboard.com/showthread.php?t=7093
Has info and a link to more details of modern FFM designed for use with RBs and to make bailing a piece of cake
I understand what you all have said, but The resp. was geared for the aga, which I have had problems with and am not a big fan of. I have a round head ans face what masks are good for someone with thoes fetures???
Field of vision is VERY inportant to me
so what would you guys recomend???
Field of vision is VERY inportant to me
so what would you guys recomend???
I AM a big fan of the AGA mask, however, not for rebreather applications. Probably the biggest problem with using a full face mask for rebreathers that hasn't been mentioned, unless I missed it in the above posts, is hydrostatic pressure. When the mask becomes the top of your loop, there is a tendency for the mask to dump gas. A bite mouthpiece as in the M-48 is necessary. The M-48 is the best mask for this application, without a doubt.
All the other issues mentioned above are valid. Safety factor is certainly one of the most important, convulse underwater with a standard bite mouthpiece DSV, and most likely we'll be talking about you here and sending flowers to your loved ones. More have been saved by full face masks than have ever been hurt by them. With that said, they are specialized equipment requiring specialized training.
I would have to argue the use of hand signals and video (?) for communications. Hands signals are fine provided someone is watching you and that they can see you in the first place. Video and re-dive a deep dive because you missed some minor detail that could have easily been taken care of by asking a simple question? Diving isn't a static endeavor. Communications allow you to easily and effectively work a task and deal with issues as they come up. I'm always amazed at the reluctance to take advantage of a technology that's readily available. But, then again, if humans were supposed to swim underwater, God would have given us gills, I suppose...
All the other issues mentioned above are valid. Safety factor is certainly one of the most important, convulse underwater with a standard bite mouthpiece DSV, and most likely we'll be talking about you here and sending flowers to your loved ones. More have been saved by full face masks than have ever been hurt by them. With that said, they are specialized equipment requiring specialized training.
I would have to argue the use of hand signals and video (?) for communications. Hands signals are fine provided someone is watching you and that they can see you in the first place. Video and re-dive a deep dive because you missed some minor detail that could have easily been taken care of by asking a simple question? Diving isn't a static endeavor. Communications allow you to easily and effectively work a task and deal with issues as they come up. I'm always amazed at the reluctance to take advantage of a technology that's readily available. But, then again, if humans were supposed to swim underwater, God would have given us gills, I suppose...
Life-Is-Good-Diver
Contributor
I'm going to watch this tread. I was over deepccr's house last night, he has a Kirby morgan , ( OC ) , and a few FFm's, like Aga, etc. I bought a rec one off him last night, a Neptune 2, for OC, i like the communciation's part you can add also. He has a few, im going to try this one first, then try the other's he has as well.
PS, I saw a MK-15 last night for the first time !! Production on the unit was 1980, nice unit!
PS, I saw a MK-15 last night for the first time !! Production on the unit was 1980, nice unit!
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