Skydive bug Mk3i 51mm

4650905 said:

When I skydive, I set jumpmaster as support suggested. I have switched power save to extended to avoid the power save mode.

„it is recommended to start an activity, SUCH AS Track Me OR Jumpmaster“

https://support.garmin.com/en-US/?faq=cJL7KD1StQ6p3LqPBGdWw9

The support article says that you should START an activity. When you START an activity it does NOT go into Power Save mode.
I suspect that you have called up the activity profile but have NOT started it.
the Jumpmaster activity only starts after entering the required data for HAHO / HALO or static line and other parameters. Finally you have to select data for DIP and HARP to START the activity profile. If you do not finish the setup, you will not be able to start Jumpmaster and it will be in standby. After a certain time it will go into PowerSave mode because you have not started it.

Jumpmaster was designed for the military to determine the landing point for jumps with a round canopy.
Today, at least in sport jumping, parachutes are used that can be steered.

In addition, when sport jumping you are usually dropped more or less directly over the landing area, which makes the jumpmaster really useless.

Since the Jumpmaster mode is completely useless for sport jumping, I recommend simply STARTING  (The watch records activity data only while the activity timer is running.) a different activity profile!

https://www8.garmin.com/manuals/webhelp/GUID-9183E86B-2399-4CFC-AB50-EAFC6D6ED326/EN-US/GUID-90B3EF66-C7DC-4BB5-A1A3-C07E1E9E7A57.html 

4650905 said:

I would like the watch to operate when I skydive.

You can use trackMe, for example, as described in the support article, or create your own activity profile. 

WARNING : Never use the watch as a primary altimeter ! Garmin obviously uses a filter. Thus, the watch is not able to provide a real time output of the correct altitude while freefall !

The use of an altimeter designed for skydiving is absolutely necessary!

Always blue skies 

Thank you for your reply, and the chuckle.

I do, indeed, "start" the jumpmaster mode .. and press GO TO HARP. It goes into the jumpmaster screen showing altitude and more.

Then 

Power save mode starts in 30 seconds. On the last dive, I changed power save to extended. But it seemed to switch itself back. Unfortunately once I start the jump Master mode and start the dive, I'm no longer looking at my watch I'm watching my altimeter. A few times I've tried to glance at my watch the lights too bright and I can't see it.

Ideally, I'd like the watch to track my dive how many seconds long it was how much free fall stuff like this but I don't get that it will do that yet

Definably feels buggy.

4650905 said:

Ideally, I'd like the watch to track my dive how many seconds long it was how much free fall stuff like this

Have  you tried another activity profil ? 
I have created my own "skydive" activity profile. The freefall time logically results from the speed and deceleration at deploy the canopy.

Thanks, will try. Can you tell me what the specs are of your skydive activity?

You can compile your data fields as you need them. E.g. speed, altitude etc