Developer Craig Hockenberry does a deep dive on how the Apple Watch interacts with water:
Like other iOS devices, the Apple Watch uses a capacitive touchscreen. Using our bodies as a conductor, the screen senses changes in capacitance using an electrostatic field that surrounds the display. When you surround your body and screen with a conductive liquid, that dynamic is shot to hell.
Unless you’re swimming in distilled water, the touchscreen on your Apple Watch just won’t work.
A fascinating and thorough read. I’ve yet to be brave enough to even wear my Apple Watch in the shower, but Craig’s experiences are enough to convince me that the Watch would be totally fine with a quick dip in a lake or the ocean this summer. (As he says, the most important thing, particularly after swimming in the ocean, is rinsing it off to prevent corrosion.)
Personally, I’ve worn my Watch plenty when working out in the gym, and agree with his assessment about the user experience of the Workout app being somewhat sub-par. I also sympathize with the frustration that leaving the Watch off for certain activities means that not all your exercise gets reflected in the Activity app. I’ve yet to wear my Watch during an ultimate game, though that’s less about damaging it than worrying that I might injure someone else. But it does totally look like I didn’t work out at all those days. Alas, c’est la vie!
—Linked by Dan Moren