Pros & Cons of Using a Full Face Mask

[Dive Right In Scuba]

Just buy it and come Ice Diving with us

You and I will play a few holes of golf under the ice and taunt each other thru the underwater comms.....It will be great!!!

 

[Solitude Diver]

I can see (at first glance anyway) certain advantages when using with rebreathers. As it is likely you will pass out before dying, and there is a change your buddy would be able to switch you to bailout gas (without removing mask). I’ll need to explore this in another board/forum.

Seems to be the whole gas sharing issue in OOG situations is minimized with ponies, side mounts, etc. As this is the technical forum, wouldn’t most have back up gas anyway? Couldn’t you just put an alt reg on your bottom/travel mix or something if it is a concern? Or have your buddy carry a pony, etc. and he won’t need to rely on you. I would think you could plan around these obstacles if you want a FFM.

As for my safety…..I like the manifold/block to switch gases with. I think I’ll look for one to incorporate into my rebreather bailout system, so I can keep the loop in my mouth and switch to multiple gasses.

Anyone using a FFM with rebreathers who could comment?

 

[Solitude Diver]

I started doing some research on the whole FFM and rebreather thing. Right off the bat, I see that there is a whole different consensus than what is on this board. Different configurations I know, but the attitude thoughts seem to be different all together.

Might be worth seeing other perspectives and how others solved some of the issues discussed in this thread. I am beginning there is a place for them in tec diving as ox-tox and other issues become a greater threat.


FFM's - Rebreather World Forums

 

[rjack321]

The M-48 has a nice looking RB attachment. Its too bad its only available to the military.

I are your pushing your scrubber to the max or something? Why/how are you concerned about unconciousness?

 

[muddiver]

The M-48 has a nice looking RB attachment. Its too bad its only available to the military.

I saw one on ebay for sale

 

[Otter]

...snip... I have to wear 39lbs of lead to keep down the AGA mask (bouyant!), the surface supply hose (with comm wire), and an AL63 which is supposed to be "backup" gas. I wear 28lbs diving my ordinary single steel tanks in the same drysuit. ...snip....

Just for clarification purposes to those who are less familiar, the vast majority of the difference in lead comes from the switch from steel to the AL-63. The AGA is positively buoyant, but I never add any lead if that is the only change I am making. While my longest dive in an AGA is probably 90 mins, I have heard anecdotal 'complaints' from divers that are in the water for 5-6 hours that the extra buoyancy cause more neck fatigue....for those, Interspiro makes a weight kit which weigh about a pound.

 

[rjack321]

Yes, the AGA is about 1.5lbs positive. I haven't been in the water so long as to experience unusual neck fatigue.
It all adds up.

 

[Solitude Diver]

are your pushing your scrubber to the max or something? Why/how are you concerned about unconciousness?

Deeper diving resulting in reduced scrubber affectiveness, and possible heavier workloads in wrecks or currents leading to higher exertionand C02 breakthrough is just one issue. There are other factors.

The site I posted above discusses the issues further.

 

[mntdiver]

The M-48 has a nice looking RB attachment. Its too bad its only available to the military.

I are your pushing your scrubber to the max or something? Why/how are you concerned about unconsciousness?

Hypoxia, hyperoxia and hypercapnia. All can result in undesirable effects. A full face mask will afford some opportunity for survival that may not be available with a bite mouthpiece DSV.

 

[mntdiver]

For the vast majority of divers that feel they require weights for the AGA mask, more often than not the mask is improperly adjusted. Over tightening of the top strap can result in the sensation of the mask wanting to come up off the face. The head harness needs to be centered on the back of the head so as to pull the mask evenly back on the face. Over tightening of the top strap will center the strap higher on the back of the head, pulling the mask up on the face. This also results in the sensation of the mask being buoyant and jaw fatigue. Improper sealing of a mask over a hood can result in hood inflation and wasted gas, this can add to neck fatigue. In general, I find the buoyancy of an AGA mask is insignificant and inconsequential. But, I'm old school, a couple of extra pounds to cover an empty tank at the end of the dive and I'm fine. I've never been one to trim to the pound or half pound here or there...