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Garmin Descent MK1 Comparison Graphs

Discussion in 'Computers, Gauges, Watches and Analyzers' started by ATJ, Mar 23, 2018.

  1. ATJ

    ATJ Barracuda

    # of Dives: 1,000 - 2,499
    Location: Sydney, NSW, Australia
    I was bored today because it's too rough to dive so I put some charts together comparing the Descent MK1 with my Shearwater Perdix AI (and Citizen Hyper Aqualand and Oceanic Atom 3.0).

    I've only had the chance to do one dive so far with the Descent MK1 so I'm using that dive.

    Here is the depth comparison between the Descent MK1 which was on my left wrist and the Perdix AI which was mounted on my camera rig. I usually hold my camera rig horizontal in front of me with my left hand so the two devices will be in the same plane most of the time. There would be some cases where I may use my left hand to steady myself while taking photos (with my right hand) which I think explains the few deviations.


    The water temperature comparison is between the Descent, Perdix, Hyper Aqualand and Atom 3.0. Oceanic dive computers are notorious for reading low. The Perdix typically takes a while to catch up with the water temperature but once it does is close to both the Garmin and the Citizen. I regard the Citizen as being most accurate but it only records the water temperature every 5 minutes.


    The NDL comparison is just between the Descent and Perdix. Both are on the same conservatism (Medium) and so it is expected they'd be pretty close.


    Attached Files:

    stuartv, Jay and DaddyJr like this.
  2. KenGordon

    KenGordon Rebreather Pilot

    Very interesting.

    How did you extract the NDL history for the third graph?

    The spike at 23 minutes illustrates the extreme sensitivity of NDL times. 2m shallower on a bimble and the NDL jumps more than 50%.
  3. ATJ

    ATJ Barracuda

    # of Dives: 1,000 - 2,499
    Location: Sydney, NSW, Australia
    For the Perdix it is available from Shearwater Desktop if you export as CSV (or the other formats, too).

    For the Descent, I imported the FIT file into Diving Log 6.0 and exported Profile 4 as CSV.

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