What should I do to make Apple Watch series 3 waterproof

EXTREMELY IMPORTANT NOTICE- Apple Watch is water resistant, not waterproof. There is a HUGE difference.

Activating Water Lock mode DOES NOT make your Apple Watch "waterproof".

Before swimming with your Apple Watch, PLEASE take a moment to read these two articles about using your Watch in the water, and what Water Lock mode actually do.

Water Resistance- https://support.apple.com/en-us/HT205000

Water Lock- https://support.apple.com/en-us/HT210931

Swipe up from the bottom of the watch face to enter the Control Center. Then tap the water drop icon.

When you have finished swimming, press the Digital Crown and then continuously turn it until the sound stops and all of the water has been expelled from the mic & speaker.

ASC - Late 2012 Mac mini, macOS 10.14.6; Watch, series 5 GPS/cellular, watchOS 6.2; iPad Air 2, ipadOS 13.6.1; iPhone 8+, iOS 13.6.1; TV 4th Gen, tvOS 13.4.8;  HomePods, audioOS 13.4.8 and Airport Express w/ Airplay 2