Garmin Descent MK2

[scubadada]

On a dive, an AI dive computer does exactly the same calculation but only over the last n minutes, where n could 1 to 5, It tells you how you are currently doing in terms of air consumption but it can also calculate how long your remaining air will last assuming you keep the same air consumption and stay at the same depth.

But my Oceanic dive computers and my Perdix do this. I find the Oceanic very accurate for the whole dive. The Perdix seems a bit conservative at the start of the dive but gets more accurate towards the end of the dive.

I have over 1900 dives on AI Oceanic computers. The air time remaining is very accurate, including the safety stop or deco stops. I only have 200 dives on my Teric but share @ATJ observation. The gas time remaining does not seem very accurate in the early dive, but corresponds pretty closely with the Oceanic toward the end of the dive. No idea why there should be this discrepancy.

 

[waterone]

The Garmin Connect app is not that great for displaying dive data. This is my dive from yesterday:
View attachment 620224

Is your app up to date?

Connect seems to display all the dive data that the dive app will and it auto syncs with extra data and pictures that i have added to the dive app.

 

[ATJ]

Is your app up to date?

Connect seems to display all the dive data that the dive app will and it auto syncs with extra data and pictures that i have added to the dive app.

It is. This has been happening regularly for the last month or so. Saturday's dive displayed fine. Sunday's not. Now none of them display correctly in Garmin Connect. They show up fine in Garmin Dive and on the web but in Garmin Connect - just crap.

 

[waterone]

It is. This has been happening regularly for the last month or so. Saturday's dive displayed fine. Sunday's not. Now none of them display correctly in Garmin Connect. They show up fine in Garmin Dive and on the web but in Garmin Connect - just crap.

I can understand how it would seem like crap if it kept doing things like that to me but other than the hacker issue and no offline data(ridiculous) mine has always worked well.

Maybe uninstall and reinstall the app and see if that does anything.

 

[ATJ]

I can understand how it would seem like crap if it kept doing things like that to me but other than the hacker issue and no offline data(ridiculous) mine has always worked well.

Maybe uninstall and reinstall the app and see if that does anything.

I don't care about it that much. I don't use Garmin Connect as my dive log as I have proper apps for that.

I have found Garmin Connect to be very flakey for the 5 or so years I have been using it.

A prime example is "Edit My Day" which in theory lets you reorder the data on the My Day screen. It never sticks and reverts to the default order. Sometimes you might have your custom order for a day, sometimes it is a few minutes but it always reverts. They have "fixed" this so many times but it always breaks again.

 

[waterone]

I don't care about it that much. I don't use Garmin Connect as my dive log as I have proper apps for that.

Yours obviously has some issue that you don't care to get corrected, so its good that you have an app that works for you and what you need.

Though the connect app. ..... if functional..... does display all the dive data and more.

 

[vjb.knife1]

That is not what SAC is.

SAC is surface air consumption. It is your actual air consumption but normalised to the depth you are/were at, either currently, or average depth for the whole dive.

There are two ways you can use SAC. One is to calculate your SAC after your dive (either manually or with dive software) and you can use this to compare your air consumption between dives. The other is what many AI dive computers do where it calculates your SAC during the dive (based on your air consumption and average depth over the last n minutes) and can display the SAC plus estimate your air time remaining - much like modern cars predict how far you can go before your fuel tank is empty.

If you dive metric, SAC is very easy to calculate after a dive. All you need is starting pressure, ending pressure, dive duration and average depth (in metres):
SAC = ((starting pressure - ending pressure)/duration)/((average depth/10)+1)

An easy example. 100 minute dive with an average depth of 10m with starting pressure of 230 bar and ending pressure of 30 bar.
200 bar was consumed during the dive so air consumption was 2.0 bar/min. But as you were at an average of 10m where the pressure is doubled, SAC was 1.0 bar/min.

For non metric it is:
SAC = ((starting pressure - ending pressure)/duration)/((average depth/33)+1)
where average depth is in feet.

If you always dive with the same sized tank you can directly compare the SAC from one dive to the next. Different sizes tanks make it not so good and you are better off using RMV (respiratory minute volume) which takes the tank size into consideration.

On a dive, an AI dive computer does exactly the same calculation but only over the last n minutes, where n could 1 to 5, It tells you how you are currently doing in terms of air consumption but it can also calculate how long your remaining air will last assuming you keep the same air consumption and stay at the same depth.

But my Oceanic dive computers and my Perdix do this. I find the Oceanic very accurate for the whole dive. The Perdix seems a bit conservative at the start of the dive but gets more accurate towards the end of the dive.

This is what I thought it was, but I still do not think this is all that useful for my diving. I am much more casual about it and really don't do anything technical any longer, so I don't feel the need to calculate this. Thanks for your explaination.

 

[ATJ]

Though the connect app. ..... if functional..... does display all the dive data and more.

Yes. When it does/did work it displayed the dive data correctly but it is still inferior to dedicated third party dive apps. The Garmin Dive app is slightly better than the Connect but still a poor implementation.

 

[TuckerIdaho]

The Garmin Connect app is not that great for displaying dive data. This is my dive from yesterday:
View attachment 620224

When's the last time you updated the app? Because you have major issues. That's not even close to the summary dive display.

You're basing an opinion on something you haven't even used.

 

[Ryan Neely]

Hey, thank you for taking the time.

I can see where having all the data in one app is an advantage - IF the data is the same kind of data. Like, cadence, speed, and heart rate. I can where it would possibly be nice to have that in one place for running and biking. But, what data is there that is really in common between diving and the other activities, that makes it nice to have it all in one place?

I will say another poster did make an effort to answer my question and I could understand his answer. As I took it, he would do a hike to get to a dive spot, then dive. So, having it all in one app meant that he could see his full GPS track from (presumably) wherever he parked to the dive site, and then the dive info. No need to switch to another app and look through the dive log for the matching date/time. That seems pretty niche, but at least it is an example of a convenience to having dive data in the same app with (in this case) hiking data.

So, I'm only playing devil's advocate here for no other reason than to explore the discussion from an academic standpoint, but ...

From a systemic (and perhaps diagnostic) position, one could feasibly also track heart rate while diving and how depth or various breathing gasses affect it. It could then be compared to hiking, running, or cycling, or being at rest. If one were to experience ... not problems, per se, but ... changes? while diving having one more metric could help pinpoint the source and how to handle it moving forward.

Of course, that would mean wearing the Mk2 against the skin i think very few folks here would be doing that ... which reinforces the argument against wanting a single device one doesn't have to remove for all activities. It still has to be taken off and affixed over exposure suits, so whether you're taking off the Mk2 and replacing once you're in your drysuit or taking off the Mk2 and replacing it with the Teric, not much difference there. (Maybe wear both. One inside the exposure suit. One outside. Heeheehee.)