Tear Drop

Not totally sure as I'm still waiting for mine , however I believe it's what you press before you submerge your Watch in water , say when you're starting your swim. I believe it stops the Watch face detecting any other touch , other than the actual water/workout.

Please someone correct me if I'm wrong.

Cheers

 

To tell the watch that you're going to use the watch underwater. It locks the screen, and turning the crown ejects water from the speakers.

 

Nothing bad would happen if you didn't do this. All this essentially does is locks the screen from getting funny inputs from the water surrounding it. If you ever forget to set it don't panic. You can manually run the eject water mode at any time as well.

 

Toy watch would have still been fine.