Water may seep into your mask while you are in the water. This could be caused by hair between your face and your mask, or if the shape of your face changes when you laugh, talk or yawn. To clear the water, tilt your head back slightly and press the top of your mask tightly against your forehead. Exhale slowly through your nose forcing the water out through the lower edge of the mask. You will be able to clear all the water by following this method. Diving masks tend to become foggy. Simply rub saliva on the inside of the mask and rinse with water. This technique should prevent fogging.