Even if you forget to enable Water Lock before you get in the water, it's a good idea to quickly enable and disable it as soon as you get out of the water. That way, your Apple Watch will at least ...

Once Water Lock Mode is activated on your Galaxy smartwatch, it's ready to be worn in the water. To disable Water Lock mode after your swim, long-press on the home/power button.

The water drop icon is associated with Water Lock, an Apple Watch feature that prevents you from accidentally touching or interacting with your Apple Watch screen when you're in the water.