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Your Gradient Factors?

Discussion in 'Technical Diving Specialties' started by CAPTAIN SINBAD, Nov 20, 2020.

  1. rjack321

    rjack321 ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, WA
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    The entire concept of having an adjustable or even known GF is pretty modern. Even just 10-12 years ago it was rare to have any kind of way to track how close you were to your hi or low. Most people moved time around and/or especially added time deeper - since "deep stops" were in vogue. Even after using buhlmann based PC software it was common to add 1min stops below the 30/85 or whatever was run. Even today on basic 1 deco gas, 25mins of deco kinds of dives its pretty common to have stops below your GF low because its rare to have a first stop anywhere close to 70ft for the EAN50 switch.

    Or the ascent looks like this and doesnt actually match whatever GF you have in your computer. So its been a longstanding issue, that whatever GF low you think you are using, its almost assured that your actual GFlow is much much deeper - it has been that way for years and years
    2c84dca3463bd272856725bca313495b.png
     
    NothingClever and taimen like this.
  2. Mike1967

    Mike1967 Loggerhead Turtle

    # of Dives: 100 - 199
    Location: Victoria, Australia
    1,331
    630
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    The answer is always Shearwater :)
    You said you're getting on so if your eyes are getting tired, get the Perdix.
     
    mac64 likes this.
  3. BLACKCRUSADER

    BLACKCRUSADER Manta Ray

    # of Dives: I'm a Fish!
    Location: Taiwan
    964
    570
    93
    I also got tri focal intraocular lenses installed at the Eye Vision Institute in Sydney. Also had cataracts done at same time. They remove you existing lens and replace it with a new improved tailor made lens.

    perfect vision now in both eyes. Trifocal allows for good far, intermediate distance vision and close-up focus. 15k poorer but the lifestyle change is great no glasses ever again.

    So works great with my Perdix and my Cressi digital console.
     
    michael-fisch likes this.
  4. mac64

    mac64 ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 5,000 - ∞
    Location: Ireland
    709
    444
    63
    Thanks, eyesight is not the best so I use prescription lenses in my mask
     
    Mike1967 likes this.
  5. michael-fisch

    michael-fisch ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: Finally Lake City FL
    1,141
    849
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    I had Bausch & Lomb Crystalens HDs implanted 8 or 10 years ago, followd by LASIK operations on my Corneas in order to correct the remaining astigmatism.
    Wow, what a difference, the Crystalens are focusable IOLs so my vision is perfect at every distance from 8" to infinity. Best 7 to 8 grand I ever spent.
    Michael
     
  6. Mike1967

    Mike1967 Loggerhead Turtle

    # of Dives: 100 - 199
    Location: Victoria, Australia
    1,331
    630
    113
    Hey dude we had a lengthy discussion about this on Facebook, small world lol

    Do you ever get the halo, glare or other side effects they warn about?
     
  7. dmaziuk

    dmaziuk Regular of the Pub

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    25 min at 5 m would require loading a relatively slow tissue compartment without also loading the faster ones (and requiring deeper stops to clear them). On a no-stop dive that should've generated "light deco" maybe. I suppose it's mathematically possible to keep ascending at a rate that will clear the faster compartments without a stop, until you hit that particular TC... but on a real dive I'd call shenanigans on it.

     
  8. boulderjohn

    boulderjohn Technical Instructor ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Boulder, CO
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    I, too, find this suspicious. A 25 minute stop at 5mm is a serious decompression obligation, and it should have been preceded by an earlier stop. On the other hand, something like that could happen with a Suunto, although not on a dive such as you describe.

    A very long time ago, before I had taken any tech classes, I did a dive that produced similar deco on my Suunto Cobra. It was on my 5th day of diving on a Liveaboard, with the previous days featuring about 4 dives per day. We all skipped the normal first dive in preparation for the second dive, which was on the San Francisco Maru in Chuuk Lagoon. I went to a maximum depth of 181 feet/55 meters in the hold, and did the rest of the dive on the deck, for a total of 15 minutes of bottom time. I remember that I did more than 20 minutes of deco, and my buddy, running DSAT on his computer after having done all the rest of the dives with me that week, went up to take a nap long before me. I later realized that my personal setting had somehow been set on the medium setting, which is why my buddy had been calling me Captain Deco all week.

    I'm guessing your buddy with the 25 minutes at 5 meters did not have that sort of dive.
     
  9. KenGordon

    KenGordon Rebreather Pilot

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    25 minutes at 3 to 6 is a perfectly normal Suunto stop. Get DM5 out, set it to Zoop and go far enough over NDL to get a decent length stop, it will be at 3.
     
  10. dmaziuk

    dmaziuk Regular of the Pub

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    With no deeper stops? Considering RGBM's penchant for deep stops? Interesting...
     
  11. KenGordon

    KenGordon Rebreather Pilot

    3,606
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    Try it see what happens. The Suuntos I have owned only put in fake Pyle style deep stops which happen based on depth not time. The ‘Fused RGBM” ones I have less knowledge of.
     

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