Battery drain during scuba diving

Maybe a stupid question, but why do you not just switch of the mini 2 while diving and switch on if you are back to the water surface? Ok, maybe a little bit dangerous for the device to switch it on at the surface, because you have to open the case for that or can you switch it on, while it is still in the closed case?

Right, that's the problem. If I actually need to use it then I would have to open the dive case and switch it on first. This isn't easy while wearing thick gloves and I might drop the device.

Yeah, it would be a good functionality, if the user would be able to set the ir device via the iR remote  in a kind of sleep mode. The iR remote needs a revise anyway, so this would be a good opportunity to add that. You should suggest that Garmin as an improvement.

Couple questions about this. 

What is your tracking interval? 

What is your Activity Recording level?  High Detail?

Do you happen to have a message in the queue that it's trying to send?

It would be nice if you could effectively put it into sleep mode, but I'm guessing it's one of the above that is causing battery drain that high.  BT and Ant+ wouldn't be causing this kind of drain.  It has to be attempted communication with the satellite.

I'm guessing it's either activity recording set to High Detail, or it's trying to send a message, which it will continue to do until sent.  Can't imagine anything else that could cause that high a drain over an extended time frame.

I'm doing a test right now where I started tracking, tracking interval at 2 min, recording at High Detail, and sending a message.  Then put it under my desk where it shouldn't be able to get a signal.

While it would be nice to have the sleep setting, if it's one of these items causing such high battery drain, you could reduce the drain by changing the settings, or making sure any unsent messages are sent before diving.

Personally, I have experienced the "mins" (1 and 2) using more battery when in cover, and trying to get messages/location data out. The mini 1 was much more aggressive on the battery than the Mini 2, in my use. But I don't know how you would resolve that 100%.

I know that if I fell, like into a bad place, that had a lot of cover, I would want that thing trying to send until it was successful, Also, if I were diving, I would not want it paused while diving. If something happened to me, and somehow I float to the surface, I might not be able to unpause it. Maybe it could detect pressure off your dive watch or something

I am not actually tracking during scuba diving. Send Interval and Auto Track are set to Off. It's not trying to send any message. 

Wow.  Then I can't figure out how it could go through 15% battery.  It shouldn't even be doing 1% / hour if it isn't trying to connect to satellite.  And unless there's a bug, no way BT is using much.

If you have it set just the same when not under water, how much is it using?

Trying a test now with backlight on 100% set to Stays On.  I've never tried this, but that's the only other way I could imagine it using 15% / hour.

My earlier tests were using about 3% / hour with 2min tracking, trying to send a message, and recording set to High Detail.  Not quite fair since it wasn't moving, and could go into a low GPS state.  But it would have continued trying to send the message.

Is it possible the case is pressing in a button?

This sounds like a defective unit.

Perhaps the battery drain is repeatable if you put the dive case (with mini 2) in a bucket full of water (or something like that)? Another real dive would be the beter solution to have a look on it. I would open a support ticket with Garmin and see, what they are thinking about that.

And (sorry) two OT questions: does the mini 2 in the dive case float? Where do you put/mount it? In a bcd pocket? 

If you are back at the surface and there are (a lot of) waves, the case might slip out of hands and so it would be nice, if the mini2 in the case would float (or nor?- if you don`t have a Garmin wearable with iR remote widget).And I don´t see any possibility to mount the case...

Supplement:

a bit crazy simulation attempt: I put the switched on Mini 2 (no unsent message present/no tracking enabled) with BT connection in a cast iron cooking pot indoors (8:03am with 98% battery) and will see how the battery level at 9:03am is.

No heavy battery drain occured, only down to 97% after one hour. But maybe my attempt is not comparable to underwater behavior. So (again) my recommendation: open a support ticket.