Diving mask

A diving mask is an item of diving equipment that allows the SCUBA diver to see underwater. The mask must be constructed so that the diver can exhale through the nose into the mask to prevent the "squeeze" caused by increasing pressure during the descent in water. The mask must have a durable glass plate in front of the eyes and a "skirt" of rubber or silicone to create a watertight seal with the diver's face. A strap keeps the mask in position.

There are several specialised types of diving headgear:

• full face diving mask - often worn by working divers who need underwater verbal communication ability
• diving helmet - often worn by divers using surface supplied diving equipment
• hard hat - part of the old fashioned standard diving dress