Can I press buttons underwater?

Thanks for the info! Then I started wondering whether we can press buttons when there's water in the gap around the buttons, e.g. right after getting the watch out of water.

That is fine. I've been pressing the buttons on mine during my swimming pool sessions when my hand is out of the water. The thing is, all water-proof gaskets will undergo some degradation over time. Traditional dive watches (Sieko/ Omega etc.) require periodic maintenance but with these digital sports watches, it is just use and dispose when they wear out. Garmin's own dive watches can be operated under water though.

It is true that pressing the buttons underwater is not recommended, and not guaranteed. I am well aware of it too. However, I own an Instinct 2 since 2 years, and previously had the 1st gen of Instinct for 3 years, and I press the buttons while swimming, diving, and snorkeling all the time (even at depth), and never got a problem. That told, I do it being aware that the eventual damage may not be covered by the warranty.