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AGA Divator Positive Pressure vs Non Positive Pressure

Discussion in 'Public Safety Divers/Search and Rescue' started by kylergoehle, Apr 9, 2018.

  1. kylergoehle

    kylergoehle Public Safety Diver

    # of Dives: 200 - 499
    Location: Massachusetts
    Just wanted people’s opinions on PP vs Non PP with the Divator FFM.
  2. TC

    TC Miscreant Moderator Staff Member ScubaBoard Supporter

    We use the non-positive pressure. It only makes a difference at the surface, once you get a few inches underwater they both function the same.

    Unless you're in some really nasty stuff I'd stick with the non-positive. (Actually I'd stick with that period- if you're getting into water bad enough to make the positive pressure a requirement you should probably be thinking about going to helmets.)
    ClusterFlux likes this.
  3. kylergoehle

    kylergoehle Public Safety Diver

    # of Dives: 200 - 499
    Location: Massachusetts
    I have the Non-PP version yet the majority of my team have the PP, so I was looking to see what others opinions are about them. I personally just love that mine doesn’t free flow at the surface the way some of theirs would if they accidentally hit the switch. Thanks for your input!
    Last edited: Apr 10, 2018
  4. northernone

    northernone Great White Rest in Peace ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Currently: Cozumel, from Canada
    Inexperienced, we're happy with non-PP. Not into things nasty enough to need PP and with surfacing to rough conditions I don't miss the potential free flow. (Only have 5hrs on PP, so my opinion comparing the two isn't worth much)

  5. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

    # of Dives: I'm a Fish!
    Location: Greenville, South Carolina, United States
    if tuned properly they should freeflow about the same volume regardless of depth. If your breathing rate is fast enough you may not notice it, but the freeflow should be there.
    That said, I would go non-PP unless you are diving in contaminated water *rare for most*

    My Poseidon is positive pressure and I'm likely going to convert over to non-PP here shortly because it's super annoying to deal with at the surface
  6. АлександрД

    АлександрД Manta Ray

    # of Dives: 100 - 199
    Location: Moscow, Russia
    For diving ony non positive pressure acceptable due to possible freflow at surface or underwater, when tou take off your mask.
    But I changed my positive pressure mask to normal very easy.
    Under the membrane cover you have plastic pad, where big and soft spring connected in to the small holes (small lips). You can made some additional turns of this spring in to that lips, that makes spring shorter. After that you will have normal mask :)
    northernone likes this.
  7. ClusterFlux

    ClusterFlux Angel Fish

    # of Dives: 100 - 199
    Location: Boulder, Colorado
    Couldn't have said it better!

    Our department converted all of our AGA masks to the non positive pressure over 10 years ago, and we haven't looked back since. With those points aside, there are also fewer parts to service and potentially fail.
    kylergoehle likes this.
  8. Doogie38

    Doogie38 Angel Fish

    # of Dives: 1,000 - 2,499
    Location: NY
    Npp is way to go, we used the aga for years switched to the guardian. Saves our team money form inexperanced divers cranking the straps down and ripping the silicone skirt which then you need to replace it. I also like the SBV (surface breathing valve) for backup divers to be ready to to go without being in air.

    Actually installed some in the aga, just rember it is another step/failure point. Positive pressure not a huge fan, if water is that bad you should use hard hat. I see it as a waste of air, if it gets ripped off under water or again inexperanced comes to play with new divers on serface don and doffing.

    We dive in zero vis and sometimes nasty current. Comes down to cost and replacement of gear. Again found the guardian to be cheaper to maintain with out safety compromises. Also balanced first and second stages makes a huge diffrance.

    I have seen some departments cut corners on first stages where they are not giving the second stage “enough air”. When I train other departments I let them try my set-up and they can’t belive the diffrance. (They thaught that was the way the aga or guardian breathed lol
  9. tbzep

    tbzep Public Safety Diver

    Can you elaborate? OTS says 1st stage at 135 and John has said up to 150 is fine. I've adjusted our 2nd stage to spec, to the gnat's whisker of free flow, and it is still not an easy breather, especially during heavy work. Compared to a good conventional 2nd stage it seems like you're breathing through a coffee straw.
  10. Ditchdoc383

    Ditchdoc383 Angel Fish

    # of Dives: 100 - 199
    Location: Indianapolis, Indiana
    Dove positive pressure for years, just went to demand. Love it!!!!

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