Few months ago, I put my S9+ underwater at a swimming pool to take a photograph.
I had no fear to do so since I had already put the phone underwater a few times.
So I put the phone underwater and took several photos using the volume key and then I kept it away from the pool. The phone was underwater for less than a minute.
After an hour, I noticed vapour on the selfie camera glass, then the screen started to blink and went completely black after about 3 hours.
I had to replace the display and cost me a fortune for the repair.
Upto this day, I'm not entirely sure how or why water got into the phone - The phone was sealed, sim card tray was tightly in position, the phone was very close to the surface of the water. (no more than 1 ft)
My only theory is that your device loses the water resistance if you click the physical button underwater.
So, if you insist on exposing your device underwater, for whatever the reason, avoid clicking the physical buttons while you are at it.
