Recommendations for Mouthpiece Retaining Devices for IWR

[rjack321]

The issue isn't simple reg retention, it's preventing water ingress during a seizure. A simple bungee necklace like you'd use on an OC second stage is inadequate for preventing water ingress into your airway/rebreather loop. The Drager/Revo gag straps prevent water ingress. That's the important part.

I'd say "limit" - some water is likely to go around the corners of your lips. That's actually the main reason I started using one, the sealing flange helps keep water from pushing past my lips when I the scooter. I didn't have the issue on OC but the loop hoses are more drag and on CCR you aren't continuously clearing the mouthpiece either.

 

[JohnnyC]

I'd say "limit" - some water is likely to go around the corners of your lips. That's actually the main reason I started using one, the sealing flange helps keep water from pushing past my lips when I the scooter. I didn't have the issue on OC but the loop hoses are more drag and on CCR you aren't continuously clearing the mouthpiece either.

Very true. I'll edit.

 

[Michael Guerrero]

I know you said no FFM, but I bought the Spectrum, which is about half the price and I hook up my own reg to it. Might be worth a look.

 

[АлександрД]

Hey! here is good idea, in another SB topic Manta bite mouthpiece?
it has similar shape with old soviet mouthpieces

just add two пукля (puklya) (rubber button, or two pin plastic device, I`d found name "Sam Browne stud")

and you will have desired device

but one bad thing - price for this mouth piece-of-s..ilicone...

 

[Kevrumbo]

Shop | Ocean Technology Systems

As a potential less expensive alternative to a FFM on Open Circuit.

Note: don't use anything like an Aqualung ABS Octopus as a 2nd stage reg attachment -the WOB even at 9msw is terrible through the mask. . .

 

[rjack321]

View attachment 457781
Shop | Ocean Technology Systems

As a potential less expensive alternative to a FFM on Open Circuit.

Note: don't use anything like an Aqualung ABS Octopus as a 2nd stage reg attachment -the WOB even at 9msw is terrible through the mask. . .

Ohhh that looks plausible. Is the dead space enormous?

Why do you think the WOB is so high? Is it better when using a more sensitive reg?

 

[Dr Simon Mitchell]

Hello,

The committee's advocacy for mouthpiece retaining devices was based on data from a French military study reporting 50 loss of consciousness events in rebreather divers all wearing these devices, with only 2 drownings. The divers were all accompanied, but as would a diver undergoing IWR be. This is a strong signal that these devices are effective. The Drager device has several design features that make it particularly so and is well worth the admittedly high price.

One point that I'm not sure if they addressed or not is that you'll still need a switch block of some variety for them to be able to switch back to air/nitrox.

I (and the committee) would not agree with this. The recommended protocols do not include air breaks, and if a diver develops symptoms of oxygen toxicity or has a seizure, they should be brought straight to the surface without any attempt to switch them off oxygen.

Simon M

 

[Kevrumbo]

Ohhh that looks plausible. Is the dead space enormous?

Why do you think the WOB is so high? Is it better when using a more sensitive reg?

Aqualung ABS through a QC6 work-of-breathing was bad enough: coupled with the dead space of the mouth mask was even worse.

I'd say try with a better performing 2nd Stage attached before you buy the mouth mask if you can. Check that you can form a good seal without gas and/or water leakage. . .

 

[Michael Guerrero]

The recommended protocols do not include air breaks

I was surprised to read this. I pulled out my Navy Dive Manual v6 and discovered that their decompression procedures call for air breaks, but their recompression procedures do not. I think my surprise is because a diver doing recompression has potentially already had hours of oxygen exposure. Adding another 3+ hours of submerged O2 exposure, which the body seems to tolerate less well, would approach the exposures encountered in dry chambers. My recollection is marked decrease in vital capacity with long O2 exposures, those on the order of chamber treatments.

 

[nadwidny]

Ohhh that looks plausible. Is the dead space enormous?

Why do you think the WOB is so high? Is it better when using a more sensitive reg?

At $85 I would get one to try but they don't ship outside the US.

Aqualung ABS through a QC6 work-of-breathing was bad enough: coupled with the dead space of the mouth mask was even worse.

I'd say try with a better performing 2nd Stage attached before you buy the mouth mask if you can. .

Or try a QC4.