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New aqua lung mistral review

Discussion in 'Vintage Equipment Diving' started by jcarpini, Jul 31, 2010.

  1. John C. Ratliff

    John C. Ratliff Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Beaverton, Oregon
    I looked and looked at the New Mistral when it came out and was available at the LDS. I didn't buy it, even though I figured that it was a pretty good performing regulator. The reason was that it would not fit my double tank configurations to place it in a good position; that small hose kept getting in the way. But I wanted to get it to disassemble it and use the second stage as a front-mount; that would be a first for a double hose regulator commercially available. Never did though, so that experiment did not happen.

  2. duckbill

    duckbill Solo Diver

    My experiences with mine have been different.

    It would freeflow whenever I rolled backwards. Probably set too sensitive. But as sensitive at it is, I wouldn't say it breathes any better than my DAAM. I would venture to say that you might want to retune your DAAM if you found it didn't compare to the new Mistral. On the other hand, I must admit that none of my dives on the new Mistral have been all that demanding, so maybe at depth or working hard it might outperform my DAAM, just as I would expect my RAM to as well.

    Also, as John also found out, the new Mistral has serious trouble fitting my doubles properly- that is, when the doubles are properly configured with the post down. I have to flip the reg over to fit my twin 50s, or I'd have to move the backpack way too far down. So, the hoses end up being reversed. No biggie, but somewhat inconvenient to have to reverse the mouthpiece just for those tanks. The reg just sticks out way too far, much further, even, than the Phoenix, and doesn't work well with a backpack.

    Yeah, I have one to call my own, and I'm glad of it. Kind of a historical moment in Aqua-Lung's modern history. Bless them for trying, but they should have made a real, honest-to-goodness double hose regulator from the ground up, instead of piecing together a Frankentitan freak.
  3. elmer fudd

    elmer fudd Solo Diver

    # of Dives: 200 - 499
    Location: Puget Sound
    So how much effect do you guys think not having a big diaphragm, (unlike virtually every other double hose), has on it's breathing? My understanding is that a big diaphragm makes the valves more sensitive and hence makes breathing easier. It would seem to me that the new Mistral is at an inherent disadvantage in this regard.
  4. Nemrod

    Nemrod Solo Diver

    That plus the weak venturi effect are two of several design flaws that limit the performance of this regulator to the Loser category.

    This regulator is not vintage, it's many faults have been discussed over and over, why bother again?

  5. John C. Ratliff

    John C. Ratliff Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Beaverton, Oregon
    The Trieste II also had a very small (relatively) diaphragm, one which had a permanent molder-in effect which cause by itself a 1.5 inch plus increase in suction effort. But I hand-made a diaphragm without this problem, and with several other modifications to the venturi, made a regulator with a suction effort of under 0.5 inches of water pressure. So size alone does not cause the problem.

  6. USdiver1

    USdiver1 Divemaster

    # of Dives: 2,500 - 4,999
    Location: Southwest Ohio
    Unfortunately for us, Aqualung DID make a real, honest-to-goodnes double hose regulator from the ground up - the MENTOR. It's just not for sale to the public, only the Navy need apply.

  7. SwimJim

    SwimJim Manta Ray

    You mean like this?

  8. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    Hi Jim
    Thanks for the picture.

    I have been meaning to post, but I don’t seem to find the time.

    Yes, I have done a bit of experimenting with regulator diaphragm position. The new Mistral is a natural to separate the second stage and first stage. You can accomplish a similar effect by just taking of your tank and placing the double hose regulator on front of you. A small tank can be helpful.

    With the second stage below the diver any regulator breathes well. There is no need for venturi assist since the regulator/ diver system becomes an overpressure system. Exhalation becomes a bit harder, but not bad at all.

    The experiments were fun and if I ever have some spare time I will play with it more, but I prefer to not have anything on front of me. It becomes a bit cumbersome.

    BTW John
    I have seen pictures of an Australian commercially available chest mounted regulators. Yankeedownunder at VDH shared several pictures of such commercially available regulators. There might have even been more that one company that offered that option in Australia.
  9. Double Diver

    Double Diver Solo Diver

    # of Dives: I just don't log dives
    Location: Boca Raton Florida
    Luis I noticed you have the up grade kit on you Mistral mouth piece, I have put mine on my Mossback MK3 and it works quite well. And where did you get the snazzy hose weights.
  10. Luis H

    Luis H Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Maine
    I did try the elbow upgrades, but I didn’t like it. It makes the mouthpiece assembly even larger and clumsier. I did replace the tie straps with the plastic hose clamps from Aqua Lung.

    The new Mistral mouthpiece is a great performer from a low resistance to flow rate, but IMO it is too bulky and large. I wear a very low volume mask (Scubapro Orbit or Atomic frameless) and the large mouthpiece gets in my field of vision when I look down. I prefer the vintage curved mouthpiece (or the silicone reproduction) since it is very low profile.

    The low flow resistance of the new Mistral mouthpiece and large diameter hoses are needed with a re-breather since the gas flow in a re-breather is totally passive. The diver has to push and pull all the gas flow. The design of the hose loop and mouthpiece in the new Mistral were adapted from a re-breather design (when Aqua Lung introduced the new Mistral they either had part ownership or had a business relationship with Draeger).

    In a decent (and properly adjusted) open circuit regulator most of the flow energy comes from the pneumatic assistance of the compressed air. The diver's suction only triggers the flow mechanism.

    I did try the new Mistral mouthpiece with one of my Phoenix RAM, but did not find it to have any advantage over all.

    Some of my hose weight came from a re-breather supplier (I can’t remember who), but then I found that the exact same stainless rings can be bought from a number of marine a boating supply companies for a bit less (they are still not cheap).

    Just do a Google search for “stainless steel rings hardware” and you will find many suppliers.

    Here is one example:
    Sea-Dog Stainless Steel Rings
    Last edited: Aug 8, 2010

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