Turn Digital Crown to unlock and eject water
I have purchased Apple Watch 5 series 44 mm in November 2019. Today the watch is displayed the message:
Turn Digital Crown to unlock and eject water
That means that the Water Lock was activated in the Control Center of your Watch. Turning the Digital Crown unlocks Water Lock and expels any water in the microphone or speaker chambers.
ASC - Late 2012 Mac mini, macOS 10.15.2; Watch, series 5 GPS/cellular, watchOS 6.1.1; iPad Air 2, ipadOS 13.3; iPhone 8+, iOS 13.3; TV 4th Gen, tvOS 12.4.1; HomePods, audioOS 13.3 and Airport Express w/ Airplay 2