Swapping to new mouthpiece U/W?

Don't think all the ranting about pre-dive checks is valid, a brand new out of the packet mouthpiece could fail due to unseen moulding fault, ditto mask strap. So I think its a personal call but I'd only consider it for monster dives.

+1


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Do you guys actually have rips often? I must be lucky but in over a thousand dives on OC never had a rip.....I've bitten through many but never had a rip.....
 
^^ What he said. Don't buy crap.

Have used Poseidon, Apeks, and Draeger mouthpieces on rebreathers for the last, uhh... deecade at least. Never have seen or heard of a failure on any. We could discuss the bite-block distances on different mouthpieces and their impact on WOB but that would be subject for another thread. The bottom line is that if you buy Chinese soft crap you are (a): going to have failures and (b): badly impact your WOB. I used Poseidon mouthpieces on Poseidon Cyklons for over 30 years of hard duty North Atlantic wreck diving and never had a mouthpiece rip... ever.

Megs are provided with Apeks, which are very heavy duty yet comfortable. Cannot imagine having one fail. rEvo used Draeger, which are softer and a little lighter duty, still never have seen one fail. Comparing those to the Hog mouthpieces that are on the dozen or so Hog regs that I use for (deco, utility, pool, etc, etc..) I have had several of those get holes where the edge of the regulator meets the mouthpiece. This is due to the sharp unfinished edge and the cheap-soft mouthpiece. So... rather than carry a spare, why don't you just buy good equipment to start with and then inspect it now and then?

And I cannot help but note that a "stretch test" of the mouthpiece is a mandatory part of a negative pressure test, don't people do them?


Buy a good mouthpiece, bearing in mind that unless they have the right distance between the bite blocks that they will impact WOB, and put them on a good DSV that has the edges of the mouthpiece oval properly broken with a radius, and you will not need to change this stuff underwater. If your DSV does not have the radius on the edge of the mouthpiece oval properly contoured by the manufacturer, you can help it with some emery cloth. Once again, these are small differences in manufacturing quality from maker to maker that make differences. Personally, I would strongly recommend ORIGINAL Apeks mouthpieces if they fit your DSV, with Poseidon being the next choice if you need something larger in the oval.


Dave

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Do you guys actually have rips often? I must be lucky but in over a thousand dives on OC never had a rip.....I've bitten through many but never had a rip.....

No.

I have never had a rip underwater. That being said, I know several people who have had an issue, even with quality "name brand" mouthpieces.

That is why I agreed that I would only consider carrying a spare on a "monster dive".


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No.

I have never had a rip underwater. That being said, I know several people who have had an issue, even with quality "name brand" mouthpieces.


Ones that were the factory specification mouthpiece on a CE approved rebreather that was properly maintained and inspected using a checklist predive, including a stretch test done as part of the negative pressure check?

Or using crap mouthpieces on cheap DSV's with haphazard predive checks?


You get what you pay for... and what you earn from your predive protocols.

Rather than deal with the crap at the back-end,, why not deal with this at the front end? :deadhorse



Different philosophies, I guess.


Dave


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Ones that were the factory specification mouthpiece on a CE approved rebreather that was properly maintained and inspected using a checklist predive, including a stretch test done as part of the negative pressure check?

Or using crap mouthpieces on cheap DSV's with haphazard predive checks?


You get what you pay for... and what you earn from your predive protocols.

Rather than deal with the crap at the back-end,, why not deal with this at the front end? :deadhorse



Different philosophies, I guess.


Dave


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Not different philosophies, just different experiences. As Michael said in the beginning, we all know you need to start the dive at 100% - that is not what we are discussing. The discussion is about what happens when after starting at 100%, what would people do or what have they done when they develop a mouthpiece issue underwater.

Because of your posts, we know that you have never had any problems underwater when using CE approved equipment.

I have seen/heard of personally Apeks, Poseidon and the AP mouthpiece ripping during a dive. From divers using checklists... And I'm pretty sure most checklists include checking the mouthpiece- at least the ones I use do.

And believe it or not, I don't only dive on or with the HH. I also teach and dive on several other rebreathers that carry the CE mark and have seen these mouthpiece failures on at least 3 of them.


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Is it really necessary to do all the 'check it first' macho stuff.

Stuff breaks mid dive. It's happened to all of us.

On one dive, I checked my primary scooter on assembly.
I checked it again when I put it in the water then repinned.
I put on a stupid number of stages and my RB. Picked up my scooter and hit the trigger to start going towards the cave. It worked fine.

The trigger jumped off 50 feet from the bank.

Someone up thread mentions Richie Stevenson. If I recall correctly, he was scootering in 100 meters plus over a 140 plus meter sea bed back to a shot line when his mouthpiece came off his loop and his loop shot back over his head. I think I recall that he ended back on the sea bed from this. That's a bad day - and not an insignificant amount of deco too :)

When you have locked the car and got all your gear on, it is nice to be able to use back up gear and not have to can the dive before it begins. I carry a halogen slug for my light on the big dives (plus the two canister lights I wear). I've brought it out twice in the water at the start of a dive when a light tested on the surface has failed to strike in water.

My buddy had the glass in his mask come away from the rubber in roughly 60 meters whilst descending a shotline in a howling current. It was fine shallow. Of course he had a spare. We regard sight as a critical part of diving so most technical divers carry spare masks. I have to say I consider the ability to breathe slightly more important than sight ;)

I don't carry a spare mouthpiece even on big dives - but with my luck it will be the next thing that goes on me at the wrong moment ;) However, the lack of a mouthpiece only loses me my RB as I can access the gas on board through an OC reg. This seemed important when setting up the JJ as a mouthpiece is arguably a single failure point which would negate large cylinders for bailout if you cannot access.
 
<insert good cheer and humor mode here>...



Not different philosophies, just different experiences.

Quite right. We have decades of difference in our experience levels.. :poke:



Because of your posts, we know that you have never had any problems underwater when using CE approved equipment.


Now, this is where I draw the line. One thing that makes me most cross is to have someone ascribe to me that I did not write, and to leave it unchallenged leaves it agreed to. I did not say this, did not intend it, and object to your doing so.

:smackbum:


I merely intended to recite that every mouthpiece failure I have witnessed was either from VERY worn out old stuff, or of cheap Chinese stuff that ought to never have been used outside of PADI basic course dives. The over the counter replacements available at any LDS are most definately NOT compatible with a rebreather of any sort.


And believe it or not, I don't only dive on or with the HH. I also teach and dive on several other rebreathers that carry the CE mark and have seen these mouthpiece failures on at least 3 of them.



I never mentioned the HH, and in fact it was the furthest thing from my mind. The Czech bits of it are high quality (bear in mind that I am an advocate of the Golem BOV), it's the USA made bits that I would not be caught dead with. I was actually thinking of the DSV of the Optima as an example of a bad DSV: The edges are not properly broken, and they cut mouthpieces. I saw these on the CNC machine where they were built (I have some aircraft parts made in the same shop, and the owner is a Mark-15 diver), and commented on it, and the owner of the shop shrugged and said that he made parts according to the drawing sent by the customer. What (Chinese) mouthpiece is installed on an Optima? Hint: It's a cheap one on a cheap DSV. The JJ-BOV DSV is not much better as far as the radius on the edge of the oval. Divematics and Halcyon are terrible, sharp as a razor. Draeger is excellent. Meg is Excellent. Poseidon Discovery BOV is excellent. Good stuff = good results. Not all stuff is excellent. Some is really inadequate. Come over to the shop sometime and I can show you over 20 different DSV's and BOV's. There are HUGE differences that impact mouthpiece cutting.



To the "big picture" of the thread, an opinion was solicited, and I have offered mine. Mine is based on the paradigm that my diving worldview is based on, which is "Would that work in the North Atlantic", or more to my actual mental image of diving "Would that work on the Doria?". The answer for this question, answered within that paradigm, is "are you friggin kidding me?". If you dive in more benign waters (like caves, no matter how far in or how deep), where you can sit quietly off in the corner and play with your gear, then go for it. Caving.... yeah.... mebbe..... Open ocean cold water wreck diving? Are you kidding me? In Grand Cayman... yeah... maybe there too.


Dave

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Have used Poseidon, Apeks, and Draeger mouthpieces on rebreathers for the last, uhh... deecade at least.

Dave, irrespective of quality you only need to catch a mouthpiece or maskstrap on a wreck, diveboat bench, stray bit of stainless on dive kit for it to break or tear. I've only used Apeks and other good brands but I've had a couple of mouthpieces get damaged.

With Dive gear- Expect the Unexpected, If it can break it will, if its so tough it should never break it probably will when you need it most and if you can without causing grief carry a spare either on you in in your tool box.

Its hardly rocket science.

Can't believe people are ranting about a spare mouthpiece and ziptie, costs a couple of quid and weigh nothing and take up no spare. Yes you can get by without so its up to you, hardly an agenda worth pushing IMO.


I would also argue if any of your kit lasts "decades" you're spending too much time playing with jets and not enough time diving :)
 
Hey Ben,

I carry plenty of spares on trips in a box that we nicknamed "the portable LDSOH". Its got things like spare DSV's. I just don't carry it underwater :eek:


Dave

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I have done this for real on a dive. Twice.

I have an AP mouthpiece in a plastic bag permanently in the inner pocket of my right-hand thigh pocket.

I had a small tear that wasn't immediately obvious at the start of the dive (I checked). I wasn't in mortal danger, but on deco I swapped to bailout reg, replaced it, and put the spare on. I always have a couple of pairs of trauma shears on me so no problems with trimming the cable tie.

The second time my buddy bit through the teat of her (OC) mouthpiece. Switched to alternate, I replaced the mouthpiece, job done.

I can't see any downsides to carrying a spare mouthpiece, and it only takes a couple of minutes to replace. I would replace it at the start of a dive, but not on the way back to the shot.

Janos
 
Fascinating. Mind you, if I recall correctly you wear very very thin gloves which make you more dexterous.
 
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