FFM at 02 stop?

[rmediver2002]

No your correct, a bandmask is a half helmet. I just meant the EXO is built heavy like a bandmask.

http://www.kmdsi.com/products/18_28.html

 

[mntdiver]

I have a couple of the ocean reefs that I haven't been able to sell.

I rarely use them and always thought that I might some day use them for deco.

I wouldn't bother unless we were spending a good deal more time on O2 than we are because the FFM introduces other issues.

I dive almost exclusively with a full face mask. The hazards of which, IMHO, are somewhat overblown. Facts are that more people have been saved by properly utilizing a FFM than have ever been harmed. This, of course, is taking into consideration that they are an advanced piece of equipment and require the training and proper application that goes along with their use.

There are three basic reasons to use a FFM:

1) Environmental exposure - Cold and/or contaminated water.
2) Physiological - (Which is what started this tread) everything from high PPO2 exposure to TMJ, denture wearers and the like. If there were ever the likelihood of unconsciousness or convulsions, a FFM will maintain a breathable environment in front of your face. Most people consider this an important feature. You know, it's that whole breathing thing we have to deal with underwater.
3) Communications - The FFM allows you to articulate/speak into an oral/nasal pocket, which is difficult, at best, with bite blocks in your mouth. Once you start diving with communications, you'll find that it literally changes the way you dive.

Now, having said that, I've always been concerned with the quality of equipment on the market. Again, this is just my opinion, but often I've seen that the water gets some what poisoned by low quality or poorly designed equipment. An individual purchases a certain FFM and finds that it performs poorly, that maybe it's uncomfortable, free flows etc. and then with a broad paintbrush paints all FFM’s as bad. When that isn’t the case at all. Sometimes it's the end user and sometimes it's just getting the right fit. With the Divator (AGA) for example, if you over tighten the top strap, you're going to hate the mask -- but then this gets back to proper training. I've dozed off with an AGA on, something I wouldn't recommend with a bite mouthpiece. Additionally, NEDU uses the USN MK20 (the AGA) for long duration dives during physiological studies and other wet pot and test tank dives.

I guess you can tell that I like the Divator, huh?

Fit will always be an issue. I'm fortunate (or maybe unfortunate) that I have what I call an "off the shelf" face. Narrow or small faces can be a problem not only with a FFM but any mask..

Then there’s gas switching and bailout, which are and always will be an issues – this could be another thread on its own.

Are full face masks for everyone? No, but with proper training and using the best equipment, I think they're certainly under utilized.

 

[MikeFerrara]

I dive almost exclusively with a full face mask. The hazards of which, IMHO, are somewhat overblown. Facts are that more people have been saved by properly utilizing a FFM than have ever been harmed. This, of course, is taking into consideration that they are an advanced piece of equipment and require the training and proper application that goes along with their use.

There are three basic reasons to use a FFM:

1) Environmental exposure - Cold and/or contaminated water.
2) Physiological - (Which is what started this tread) everything from high PPO2 exposure to TMJ, denture wearers and the like. If there were ever the likelihood of unconsciousness or convulsions, a FFM will maintain a breathable environment in front of your face. Most people consider this an important feature. You know, it's that whole breathing thing we have to deal with underwater.
3) Communications - The FFM allows you to articulate/speak into an oral/nasal pocket, which is difficult, at best, with bite blocks in your mouth. Once you start diving with communications, you'll find that it literally changes the way you dive.

Now, having said that, I've always been concerned with the quality of equipment on the market. Again, this is just my opinion, but often I've seen that the water gets some what poisoned by low quality or poorly designed equipment. An individual purchases a certain FFM and finds that it performs poorly, that maybe it's uncomfortable, free flows etc. and then with a broad paintbrush paints all FFM’s as bad. When that isn’t the case at all. Sometimes it's the end user and sometimes it's just getting the right fit. With the Divator (AGA) for example, if you over tighten the top strap, you're going to hate the mask -- but then this gets back to proper training. I've dozed off with an AGA on, something I wouldn't recommend with a bite mouthpiece. Additionally, NEDU uses the USN MK20 (the AGA) for long duration dives during physiological studies and other wet pot and test tank dives.

I guess you can tell that I like the Divator, huh?

Fit will always be an issue. I'm fortunate (or maybe unfortunate) that I have what I call an "off the shelf" face. Narrow or small faces can be a problem not only with a FFM but any mask..

Then there’s gas switching and bailout, which are and always will be an issues – this could be another thread on its own.

Are full face masks for everyone? No, but with proper training and using the best equipment, I think they're certainly under utilized.

More technical divers have probably been killed by switching to the wrong gas at the wrong depth than anything else.

I just haven't seen a FFM comfiguration that lends itself to gas switching procedures that I would trust...and yes I have seen various switch blocks. In fact a guy recently got killed this way and it wasn't the first time he toxed either...just the first time it killed him. Give me some time and I'll try to remember where to get the specifics from.

Keep in mind that a run of the mill "technical dive" could involve a dozen gas switches or more including switches to and from stages, switches to decompression gasses and back gas breaks.

Donating gas is another area of concern. We donate the reg we're breathing which is on a 7 ft hose and the alternate is on a necklace right under the chin. I'm convinced that this is head and shoulders above having the reg to be donated clipped off someplace...maybe.

Too many problems and too little benefit on technical dives, IMO.

 

[trymixdiver]

I'd have to agree with mike here. I was using an Aga for tech dives, built my own gas swtiching block and custom hose lengths ect...

I dove it without incident for a solid year, myself and my buddy using similar gear config, only diff was he used an EXO 26 and i the Aga.

I was pretty comfortible with the gear but it was complex compared to just using 2nd stages. Gas switching and sharing are big concerns as is the actual configuration. I dont think there is a safe configuration out there, or we would all be using it. I quit using mine after i realized that it was not a safe system.

as i see it there are two ways to do it and both are flawed:

1. A system that is always connected leaves you at risk of a leak from your deco mix into your bottom mix without your knowing until its to late.

2. A system using quick dissconnects ( my old system) introduces salt water into the system and creates a serious maintenence and corroision problem.

I love my Agas but there just isnt a safe way to use a FFM while tech diving.

Andy

 

[DEEPLOU]

I'd have to agree with mike here. I was using an Aga for tech dives, built my own gas swtiching block and custom hose lengths ect...

I dove it without incident for a solid year, myself and my buddy using similar gear config, only diff was he used an EXO 26 and i the Aga.

I was pretty comfortible with the gear but it was complex compared to just using 2nd stages. Gas switching and sharing are big concerns as is the actual configuration. I dont think there is a safe configuration out there, or we would all be using it. I quit using mine after i realized that it was not a safe system.

as i see it there are two ways to do it and both are flawed:

1. A system that is always connected leaves you at risk of a leak from your deco mix into your bottom mix without your knowing until its to late.

2. A system using quick dissconnects ( my old system) introduces salt water into the system and creates a serious maintenence and corroision problem.

I love my Agas but there just isnt a safe way to use a FFM while tech diving.

Andy

Reminded me of Tony Mafitone. Designed some complex systems. (which killed him)