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FFM and rebreathers (panorama)

Discussion in 'Rebreather Diving' started by mrmints, Feb 14, 2020 at 1:53 AM.

  1. mrmints

    mrmints Garibaldi

    # of Dives: 500 - 999
    Location: UK
    1
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    Hello Scubaboard!

    (Reposted from RBW)

    As a long term sufferer of inner ear infections, equalisation problems and cancelled 2nd dives (due to mucus build up), I'm exploring the possibility of using a FFM to see if it helps. My Eustachian tubes are narrow and I have a strong histamine response, so a bit of water around my nose and mucus a.) prevents me from clearing my ears on multiple dives and b.) gets stuck in my inner ear making me at best a bit deaf, but quite often sore and uncomfortable for a couple of days after diving. Surgery on my sinus and Eustachian tubes is a possibility currently being discussed, but in all honesty, I'd rather not.

    I'm looking at a FFM as an option - it MIGHT help keep my nose dry and clear of salt water, therefore reducing mucus build up. I've been giving it a lot of thought, but have some basic questions I wonder if anyone could help with. Panorama is my first choice at time of writing.

    General questions:

    1.) How much harder is kitting up with a FFM, if at all? Can you still see your chest for example when sat on the boat with everything plumbed in and ready to go? I can't decide from pictures if it looks like the BOV/DSV is that much further away from your mouth with a FFM or not.

    2.) Can you still use a HUD like a NERD with a FFM?

    3.) what's the worst part about using a FFM?

    Questions regarding bailout:

    Using a panorama, I have read that a lot of people use the right port (as worn) to plug in bailout. I'm guessing that if your strategy is to try and keep the mask on until you have no other option but to remove it - the reg that goes in here is probably going to stay in there unless the mask come off - swapping it would involve fully flooding the mask, which (again guessing) I would have thought isn't part of the plan on a normal dive.

    1.) Is it considered best practice to always have your "deep" BO plumbed into the p-port? Or might these get switched as required?

    2.) Is it considered best practice to keep this p-ported regulator permanently isolated (inline shutoff) until needed, or is it kept on (the nose could be used as an "ADV"?!) or is this just personal preference?

    3.) Do both the BOV and the p-ported reg need inline shutoffs? (Will they both free flow when removed? I've not used a BOV for a long time, but I don't remember them free flowing when removed)

    4.) Is it best practice to have the p - ported regulator on a QD fitting, or plumbed straight into the 1st stage?

    5.) Should you have an additional 2nd stage on your deep BO? I'm thinking an uncontrollable mask flood at depth at the back of a cave...the 2nd stage for your deep bailout is tied up in your flooding mask, you want to stay on the loop, take a deep breath, close the loop, disconnect the BOV/DSV rip the mask off, then stick the p-port of the BOV/DSV in your mouth and go back on the loop...the p-port isn't the easiest thing to breath from - you flood your unit (I realise as I'm typing this, you're having a really bad day here) want to bail out, but the BO is in the mask, with another P-port...not to mention, what if you buddy has a CO2 hit - he/she's probably not having my deep B/O if it's plugging a hole in my mask! What do you FFM users do?

    6.) is there a sensible way to stay on the loop but loose the mask if you needed to? do you guys carry a spare mouth piece with you to stick over the p-port? does that work or does it just flood the unit?

    As always, any help would be much appreciated.

    Thanks!

    Chris
     
    UTscuba likes this.
  2. Searcaigh

    Searcaigh Chromodoris gordonii Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Dubai, UAE
    5,589
    4,239
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  3. Bigbella

    Bigbella Barracuda

    # of Dives: I'm a Fish!
    Location: San Francisco
    413
    295
    63
    I'll answer what I can, about the use of full face masks; though will defer to those more experienced with their use in CCR than I.

    Equalization is the 1˚ challenge with all FFMs -- to even those without potential medical conditions. A "valsava nose block" is typically used during descent, either by pushing from the chin and blocking the nose; or by pressing a panel in front to the same effect. When I have experienced sustained sinus issues; and mine are comparatively minor and seasonal to yours; I have been unable to use them, without steep investments and space-shot timing with Sudafed. In addition, not all masks are approved for use with mixed gases.

    1.) How much harder is kitting up with a FFM, if at all? Can you still see your chest for example when sat on the boat with everything plumbed in and ready to go? I can't decide from pictures if it looks like the BOV/DSV is that much further away from your mouth with a FFM or not.

    You typically cannot see your chest at all while using a FFM. The second stage strikes my sternum at less than a 45˚ tilt downward.

    3.) what's the worst part about using a FFM?

    Their potential buoyancy, bulkiness and added expense comes to mind; their higher level of required maintenance; and depending upon whether a given visor is frosted on the sides, surprisingly poor peripheral vision. Ballast can also pose an issue, almost doubling the weight of the mask, in some cases, which can be uncomfortable on a long dive. If you're prone to claustrophobia (which I imagine you're not, considering that you're cave diving), the binding "spider" head harness can be stressful for some . . .


    5.) Should you have an additional 2nd stage on your deep BO? I'm thinking an uncontrollable mask flood at depth at the back of a cave. What do you FFM users do?


    Yes, aways carry redundant, separate bail out equipment under those or similar conditions, including a split mask; perhaps, also a gas switching block for bail-out regs, and intimate familiarity with that gear . . .

     
  4. DreadnoughtNH

    DreadnoughtNH Nassau Grouper

    # of Dives: 200 - 499
    Location: Portsmouth, NH
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    Is it wrong that I read FFM in the post and suddenly became incredibly interested in rebreathers?
     
  5. -JD-

    -JD- Eclecticist ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Greater Philadelphia, PA
    453
    242
    43
  6. lowviz

    lowviz Solo Diver ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Northern Delaware or the New Jersey Turnpike
    6,784
    3,434
    113
    Very complex.

    Sorta like cave diving, piece of cake until it isn't. At that point, you better be solidly up on your s#$T. I see no reason why a newbie can't master the few required skills for a FFM.

    Problem is, the skills need to be mastered before they are required. Take a course that stresses you.
     
    Bigbella likes this.
  7. rjack321

    rjack321 Captain

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, WA
    9,300
    3,264
    113
    For me the hardest thing about FFMs (on OC) is clearing my ears. Nose blocks never worked for me at all.

    Couple other points:

    1) If you flood the mask due to the skirt ripping or the straps failing catastrophically, or the lens deciding to break or pop out etc etc You are on BO. Screw staying on the loop there's a good chance its compromised and your attention to knowing your ppO2 is going to be crap too. Bail and get the hell out (on your backup mask).

    2) Dont put flow stops on OC regs - even fully open they restrict flow and when you really need gas you need it. Plus more than one buddy has gotten an OC reg donated to them and nearly drowned because the flow stop was off.

    3) You need OC 2nd stages on all gases.
     
  8. Preach

    Preach DIR Practitioner

    # of Dives: 200 - 499
    Location: Nederland
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    I was in the same situation, i always had trouble equalizing my ears. Till the point where i had a reversed block at 30m/100ft. i managed to equalize my ears after a few minutes but had to use so much pressure while varying a little bit in depth, that my ears where painfull for a few days. After this i went to see a doctor.

    After some tests the doctor told me i had to quit diving, everything up there was too narrow. After i told him that was a no go, he told me it was operable. I didn't even have to think about it, scheduled a date right away.
    It has been 4 years since the surgery and i couldn't be happier. They did a fes surgery and also opened some nasal cavities (I hope i translated that to english correctly).
    Not only does it helps a lot with diving, but i feel better overall.

    Even when diving a FFM you will have extra risks with your condition, on top of the extra risks that a FFM already provide. For me back then there was only 1 solution, and that was surgery.
     
    rjack321 likes this.

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