what does water lock do on iwatch?

Hi

Apple Watch Series 2 remains equally water resistant regardless of whether or not Water Lock is turned on.

Planned water exposure (except swimming workouts)

If you plan to get Apple Watch Series 2 wet under other circumstances than a swimming workout (such as during general wear in a pool or when showering), you can manually turn on Water Lock first (to prevent accidental screen interactions) and then turn it off again afterwards, which also clears any water from inside the speaker - it does not turn on automatically:

• Swipe up from the bottom of the watch face to open Control Center > tap on Water Lock to lock the screen.
• When finished: turn the Digital Crown to unlock the screen and to clear water from the speaker.

Swimming workouts

Starting a swimming workout in the Workout app on Apple Watch Series 2 models automatically enables Water Lock, which locks the screen to prevent accidental interactions during your workout. To finish your workout and expel any water:

• Press the Digital Crown and the side button at the same time (which pauses the workout).
• Turn the Digital Crown, which unlocks the screen and clears any water from inside the watch's speaker (it may make a sound).
• Swipe right and tap on End.

Accidental / other exposure to water

If the watch is exposed to water accidentally at any time or if you forget to enable it before planned exposure to water, Water Lock can be enabled afterwards and then immediately turned off again to expel any water from inside the speaker (by following the same steps as above).

After swimming or exposing it to anything other than fresh water, be sure to clean your Apple Watch Series 2 by gently rinsing it with warm tap water. The watch and band should also then be dried using a nonabrasive, lint-free cloth.

More information:

Work out with your Apple Watch - Apple Support

About Apple Watch water resistance - Apple Support

https://help.apple.com/watch/#/apd707b42a5e

To enter water, it does not require the water lock to be enabled. It is just a convenience so it will not disrupt the screen and accidentally call, text etc.

There is another benefit to at least locking it and unlocking it when it is been exposed to water. When you scroll with the digital crown after setting water lock, it will make an audible tone and emit water out of the speaker.

You can enable the water lock from the control center by swiping up from the bottom of the display while viewing the watch face. The watch also enters water lock mode automatically when you start a swim workout in the workout app on the watch

When water lock is on, the Watch will not respond to taps. Turn the crown to unlock it.

About Apple Watch water resistance - Apple Support

Status icons on Apple Watch - Apple Support