Modern masks do a good job of creating a seal around your eyes and nose, but they are not perfect. Actions such as smiling or opening your mouth can cause leaks, and you may even want to intentionally flood your mask to remove fog from the inside of the lens. To clear your mask:

1. Look down and take a breath. Be careful not to inhale through your nose.
2. Press the top of the mask's frame to maintain a tight seal at the top of the skirt.
3. Slowly exhale through your nose as you tilt your head back. The air you exhale is trapped in the mask and forces the water out through the bottom of the mask.
4. Repeat these steps if the mask is not completely cleared after one attempt.