How to position a gag strap?

[reefrat]

Hi all
I finally received a Drager Safety Mouthpiece from Tecme that I ordered months ago- Martin shipped it fast but the local post is incredibly inefficient.
So far I have just tried it on unattached to anything but I am not able to find any instructions or recommendations on how best to position it. Should the strap be a the back of the neck or top/back of the head and should it be firmly tensioned or just enough to stop the BOV falling completely out of my mouth?
My motivation for buying it is twofold- hopefully more comfort plus retain the BOV in the unlikely event of a hypoxic or similar episode.
I know REVO CCR's come standard with these and strongly recommend their use so the REVO instructors must have some guidelines on how to use them but there is nothing in the manual available on-line.
Cheers

 

[cathal]

I am not able to find any instructions or recommendations on how best to position it. Should the strap be a the back of the neck or top/back of the head and should it be firmly tensioned or just enough to stop the BOV falling completely out of my mouth?
My motivation for buying it is twofold- hopefully more comfort plus retain the BOV in the unlikely event of a hypoxic or similar episode.
I know REVO CCR's come standard with these and strongly recommend their use so the REVO instructors must have some guidelines on how to use them but there is nothing in the manual available on-line.

I have been using one on a rEvo for the last three years. My understanding of the advice from rEvo is that you pull each end of the strap as hard as you can to ensure an airtight seal. As a test you should be able to relax your lips completely around your mouth piece with no water ingress at all i.e. in the event of an LOC event then your covered.

Regarding positioning of the strap look at the natural angle of the strap to the mouth piece and place accordingly. I place mine over the mask strap. And no I'm not bothered by this.

Hope this helps

Cathal

 

[TotDoc]

I started using one of these with my SF2 - I was really pleasantly surprised by how comfortable it is. I am really looking forward to using it more! On longer dives, I would always get some soreness in my jaw and some irritation on the inner aspect of my lower lip from movement of the mouthpiece, but this is completely eliminated with the gag strap. I really enjoy letting the mouthpiece just float around a bit and not worry about biting down on it so much.

The strap goes towards the top of your head, not on your neck.

As far as the tightness of the straps...I would recommend getting in the water and playing with it in your actual diving position. I make it just tight enough that when I simulate floating in the water like I have passed out that the mouthpiece stays in place without water ingress. It was not nearly as tight as I thought it would need to be when I was testing it topside.

 

[reefrat]

Thanks for the responses and I will be trying it out as soon as I get over a bout of flu....... arrrgh!

 

[Akimbo]

... It was not nearly as tight as I thought it would need to be when I was testing it topside.

I have found that as well. I haven't met anyone who had much faith in it in a convulsion or total blackout situation. A FFM is a better solution if you can find one that works with a 'breather. Has anyone seen the Spectrum Full Face Mask from Ocean Technology Systems?

 

[cathal]

I have found that as well. I haven't met anyone who had much faith in it in a convulsion or total blackout situation.

Talk to the French Navy. They reported 49 out of 50 divers who experienced loc events were saved because they were using a gag strap.

Has anyone seen the Spectrum Full Face Mask from Ocean Technology Systems?

Any idea how one is supposed to bailout wearing this?

 

[Akimbo]

Talk to the French Navy. They reported 49 out of 50 divers who experienced loc events were saved because they were using a gag strap.

Any idea how one is supposed to bailout wearing this?

Convulsion onset without any warning to a well trained pure O2 rebreather diver (Navy combat swimmer) is very rare, as is a total sudden blackout. The gag strap is very helpful in the near-blackout phase. The comment was in response to @TotDoc observation about leaking during a simulated blackout.

The photos look like a BOV "should" fit the mask. However, switching to a half-mask and second stage mouthpiece is standard procedure taught in most (all?) recreational FFM classes. The oral-nasal will "probably" increase the dead airspace problem but it "might" be as good or better than the Draeger FFM... and less expensive.

 

[The Chairman]

I went to a Shrimp last year (BOV) on my SF2 and have bought a gag strap. I haven't used the strap yet, but the BOV makes a lot of sense with it. All my bailout second stages use the same QD as my Shrimp. It's quick and easy to switch between hoses. I really like the look of that Spectrum FFM and want to try one out.

Edit: adding cooper hoses was great. They act like a gag strap in that I rarely have to hold the reg in my mouth. The short hoses do that for me. They are awesome.

 

[Chris H]

Not terribly constructive, but I had to place mine on somebody else's BOV. I couldn't make it work for me. I have since added hose weights, and that helped with a lot of the problems I was blaming on the mouthpiece. I'm using a Golem Shrimp and Cooper 22" hoses on a KISS Classic. I may have tried that damn gag strap when I had the original Golem BOV. It was difficult to adjust the strap with dry gloves on too. YMMV.

 

[Akimbo]

@The Chairman

The BOV makes a lot of sense for a first-line bailout, but a BOV second stage failure is a consideration that a switching manifold or QDs don't address. It's the same old story, how much backup can you carry and manage before it isn't much fun anymore.