The full-face diving mask, unlike the conventional two-piece snorkel, covers the whole face of a diver and which is made up of a mouthpiece and a demand valve, where the oxygen gas flows through it to provide the breathing air for the diver. This type of diving mask was designed purposely for professional diving because of its practical functions. Divers can clearly see underwater while, at the same time, protects the diver's face from unforeseen elements underwater, such as coldness of the water, polluted water, or stings from jellyfishes or corals. A diver wearing a full face safe diving mask experiences more security in breathing than wearing the conventional two-piece snorkel in the sense that in extreme cases when the diver may encounter problems like being unconscious or suffer what is known as oxygen toxicity convulsion, the diver can continue to breathe from the mask. Unlike in a two-piece snorkel set where the mouthpiece is separated and gripped between the teeth, in a situation when the diver is unconscious, there is a strong tendency of letting the mouthpiece be detached from the diver's mouth.
Depending on the design of a full-face diving mask, what should really be considered, in purchasing one, are two significant areas - the mask should provide oxygen gas to the diver and that a secure air space is facilitated for underwater vision. To be able to provide a safe and secure full face safe diving mask, its construction must comprise the following: a transparent window face plate for the diver to see, a valve connected to the source of oxygen gas, a means of removing water that may enter inside the mask, a provision for the diver to block the nose so he/she can equalize his/her ears, a sealing feature around the mask. Further, other components may be included, such as communications equipment, lights or a facility to defog the interior surface of the faceplate, and an alternative breathing has connection.
The full-face diving mask is manufactured for professional diving use, but in recent years it has grown in popularity due to the interest in recreational diving. And here lies the problem of using full-face diving masks that are not properly designed by commercial manufacturers, who are there for the profit, and may not have followed proper safety inspection and accrediting procedures of their products. If the diving mask is poorly designed, two dangerous consequences may occur: the tight-fitting head straps may be hard to remove in an emergency situation and carbon dioxide, which is supposed to be breathed out, may build up inside the mask. It is, therefore, important to purchase a full-face diving mask from an expert and accredited manufacture as well as learn how to use it from experienced scuba diving instructors.
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