10 Facts About Full-face mask

Full-face diving mask is a type of diving mask that seals the whole of the diver's face from the water and contains a mouthpiece, demand valve or constant flow gas supply that provides the diver with breathing gas.

The full face mask has several functions: it lets the diver see clearly underwater, it provides the diver's face with some protection from cold and polluted water and from stings, such as from jellyfish or coral.

Full-face mask provides breathing gas to the diver, and an air space to facilitate underwater vision.

However, some models have a mouthpiece isolating the breathing gas supply from the rest of the interior of the Full-face mask, or have a divided interior, and the main air space must then be equalised during descent by exhaling through the nose.

Soft skirted full-face mask is the more common arrangement, and is generally considerably lighter and more compact than the more sturdy and rigid band masks.

Full-face mask is generally the last piece of equipment fitted before the dive, as it is cumbersome and makes fitting other equipment more difficult by restricting the diver's field of vision, and the mobility of the head.

Full-face mask must provide a means for the diver to block the nostrils for equalizing the middle ears.

The Drager Panorama Full-face mask allows the primary demand valve to be unplugged from the Full-face mask and a bailout demand valve to be substituted.

Full-face mask provides better security of breathing gas supply than a half-mask if there is a risk of the diver losing consciousness underwater.

Free-flow type of full-face mask is sometimes referred to as a Jack Browne rig, named for a DESCO engineer who designed an early version of a full-face mask with a surface-supplied free-flow air supply.