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Gradient Factors - What is Everyone Using?

Discussion in 'Advanced Scuba Discussions' started by UCFKnightDiver, Jul 17, 2020.

  1. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
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    The salt/fresh difference is just due to ambient pressure at depth? @scubadada What kind of water is your Teric diving in?
     
  2. scubadada

    scubadada Diver Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
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    My Teric is set on salt water.

    For a dive to 80 feet on air, my Oceanic computer gives a NDL of 30 minutes running DSAT and 26 minutes running PZ+. These would correspond roughly to a GF high of 100 and 94-95. I don't know if these times include descent or are time at depth. Oceanic has no deco planner for DSAT or PZ+.

    Using the NDL planner on my Teric, I get 29 min for GF high of 99, 24 min for 90, 19 min for 80, 15 min for 70, and 12 min for 60. Again, I don't know if the NDLs include the 1 1/3 min descent time or not. Using the deco planner, dives at a GF high of 99 and 90 are no stop with a run time of 23 min, including the 2 2/3 min ascent. At a GF of 80, there is a 1 min stop at 10 ft, including the ascent, it is called a total deco time of 4 min. For GF of 70, it is a 3 min stop, total deco 6 min and for a GF of 60, it is a 6 min stop, total deco 9 min.

    Clearly, the above represents clean first dives only and does not reflect handling of repetitive dives. Seems like my Teric results differ from those of @EFX by just a little.

    For my diving, small differeces like this are inconsequential. Ninety five percent of my dives are no stop, often fairly aggressive. The remainder are light, back gas deco, usually <10 min. I dive my Oceanic VT3 on DSAT and my Teric on 80/95. They run off the same transmitter. I dive no stop based on the more conservative of two or clear the deco on one or both. I used to do a 3-5 min safety stop or pad my deco by the same amount. Now, I follow my SurfGF and make my final ascent no higher than the mid-80s, often much lower.
     
    markmud likes this.
  3. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
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    ?? My OC1 has a planner.
     
  4. scubadada

    scubadada Diver Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
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    I have an NDL planner On my VT3, just no deco planner. Your OC1 has a deco planner? Of course, my Teric has both.
     
  5. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    9,790
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    No, the OC1 is an NDL planner. I thought the thread was about NDL dives.
     
  6. scubadada

    scubadada Diver Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
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    The post under discussion, by @EFX included both no stop and deco dives Gradient Factors - What is Everyone Using?

    I think nearly all computers, even the most basic, have NDL planners. I can think of at least one, that does not. On the other hand, it has never made sense to me that computers supporting multiple gases, do not have a deco planner. For example, my Oceanic VT3 supports 3 gases. What are you going to do with multiple gases if is not accelerated deco? I have known a couple of divers who used O2 at the safety stop for their own reasons, usually a previous episode of DCS, but that would not require computer monitoring.
     
    markmud likes this.
  7. KentB

    KentB Barracuda

    # of Dives: 200 - 499
    Location: Rather be under water
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    I use 50/85
    I pad my stop times so I rarely surface at more than a surfGF of 70
     
  8. RainPilot

    RainPilot OC/CCR Instructor Trainer Staff Member ScubaBoard Supporter

    # of Dives: I just don't log dives
    Location: UAE
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    Agreed, for the majority of users. Just an additional data point, the RAID Deco40 course allows gas switching to extend multi-level NDL dives but not as a means to accelerate deco, although being on a richer gas would, in practice, result in quicker deco.
     
    scubadada likes this.
  9. tomcatbubba

    tomcatbubba Trimix Instructor | Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: Southern Maryland
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    I typically run 50/60, sometimes 50/70. It is ultra conservative I know, but I am the sole bread winner in my family and with 4 kids I am trying to buy down risk a bit. If I get a hit and need a chamber ride, Mrs. Tomcatbubba will put one foot up my butt, and the other squarely on my dreams of ever diving again.....

    Besides, O2 is cheap and I find deco stops relaxing (usually). Plus, I typically have older students in Tec classes from the local Navy base and I like the conservatism with them as well.
     
  10. ls1dreams

    ls1dreams Nassau Grouper

    # of Dives: 25 - 49
    Location: DC
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    This is just smart. I'm only a rec diver but plan to run safety stops as long as possible from this point on. Would like to get a Shearwater just to monitor surfGF/the tissue compartment view to have something fun to watch while at a safety stop.
     
    tomcatbubba likes this.

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