Questions about full face mask

[ben_wilson3301]

The main advantage of FFM is coms. It is usually used in searches by law enforcement. Once you get used to it I find myself using somewhat less air because I can breathe through my nose which is a more natural feel. Everyone is different.

 

[Vic139]

I just got certified in January after not diving for over 50 years. I have been looking at full face masks, because in April I had to have all my teeth pull because of bone disease. so far i has been very hard to use a regulator that goes in the mouth. Also Dentist said I tried to soon.

 

[HowardE]

Once you get used to it I find myself using somewhat less air ...

I think scientifically (and empirically based on my own experience with a few hundred FFM dives, and knowledge of my SAC and tracking my air consumption on an air integrated dive computer), you're wrong.

Scientifically... there is increased CO2 because of the inability to fully exhaust the air within the mask, unless you purge the entire mask. This is due to the increased anatomical dead space in the mask. Even if your oral/nasal is a tight fit, there is still a lot more anatomical dead space than in a standard scuba second stage.

Increased CO2 causes humans to breathe more. As Carbon dioxide levels go up, the pH of the cerbrospinal fluid goes down and triggers a reaction in your brain to cause you to breathe. This is the vicious cycle of increased CO2. As you breathe more, you give off more CO2, causing you to breathe more... etc. Therefore, by this process, it is natural that more air (gas) is consumed with an FFM.

I can also tell you from my hundreds of FFM dives, that my SAC is always higher than with OC Scuba.

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Also - Working divers (not just PSD's) use FFM's because you have the ability to use communications, and the ability to swim around untethered. If you're diving hard hat, you really can't swim around.

 

[RonFrank]

Interesting discussion! I dove with a couple guys wearing FFM and they gave me a receiver so I could monitor the conversation.

• There was very good communication but not as much as you may think.
• Staying together seemed easier.
• It was somewhat comforting.
• When one found something cool sharing was easier. But I did not have difficulty sharing without being able to talk. Banging/signals and pointing works well.

Overall it was a cool experience but I don't miss not being able to talk UW.

 

[Sat Diver]

Thanks everyone. The mask will not be for me, it will be for a friend who is not certified, but wants to go out on a dive with me on an upcoming vacation with a dive master. She has dived before, never completed her certification and is not really interested in doing so. She wants to be able to just occasionally go out on dives during a vacation. She is uncomfortable with the idea of her mask flooding and that is the primary reason she never finished getting certified, so I thought that this might be a possible solution?

That is a very bad idea .