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Error in descent rate and ascent rate calculation

YoFoKo
over 1 year ago

The apnea mode has a persistent error in the calculations of the ascent and descent rates as well as hang time. 

For my “touch and go” free dives—ie, competitive freediving, the calculation includes a non-zero hang time. And it’s not just not zero, it’s like 20-30 seconds. Touch and Go suggests it should only be a couple seconds at max. So then the descent and ascent times and rates are calculated with the remaining time. Too long of a hang time means the rates are calculated over a shorter period thus the rates are too fast!  

And this matters for freediving. It’s great to get immediate feedback on how fast your dive was, and garmin recognizes this by add a variometer. But if the calc’s are wrong, it’s useless. 

I’ve owned two MK2’s both suffered from this error. I think it’s a problem with the software

PLEASE FIX  

  • 0 over 1 year ago in reply to Basti-Garmin

    I'm using Garmin Dive version 2.14.1.1 (latest iOS version). Your interface looks a bit different.

    I was mistaken in my last post. It may have been different in a previous version, but the current version actually starts from time zero at the beginning of the dive session (start of your first dive) for the session timeline. If you go into the individual dive timelines, each one starts with the end of your last dive, or beginning of your surface interval. I don't need this information. I would rather have every timeline start with the descent. I hope this makes sense.

    I've edited my last post to reflect this, in order to avoid any confusion.

  • 0 over 1 year ago in reply to 6538456

    Agree - surface interval doesn't need to be part of the timeline/chart

  • 0 11 months ago in reply to Basti-Garmin

    I don't recall seeing this before, maybe it is a recent app update(?)...

    Individual dives include a velocity chart with the option to use velocity smoothing. The help description even mentions using smoothing in free immersion. 

    Plus, a spot check of a few total dive times seem like they are now within a rounding error of equaling the sum of descent, hang, and ascent times (it used to be way off). 

  • 0 8 months ago in reply to 6538456

    I have been experiencing a problem with velocity on descent and ascent on CWT dives. I wear 2 devices. A Garmin Descent MK2 on my wrist and a Suunto D4F inside my hood to hear my alarms. I was concerned about the variabilities of velocity especially on descent. I set my Suunto to a sampling rate of 1 second. The Suunto data shows descent velocity of 1+m/sec compared to the Garmin velocity dropping to .03 m/sec.

    The velocity data for Garmin is incorrect and needs to be fixed

    Your solution of depth and time to calculate velocity would be a great solution.

  • 0 3 months ago

    Hi there!
    Have this issue have been removed from Mk2 Series? Any info? What about Mk3 Series?

  • 0 3 months ago

    Hi there!

    have this issue been removed from Mk2 Series ? What about Mk3 Series? Any info?

  • 0 3 months ago in reply to Mr Falcon

    I have been using it since 2021. The above-mentioned issue first occurred on October 17, 2024, and it has not been resolved yet. I received a response from the Taiwan headquarters technical team stating that it was due to a calculated slow diving time. However, this explanation does not make sense to me.