Full face snorkel masks are all the rage today. But are full face snorkel mask safe to use? Since their launch in 2015, they have become the most popular snorkel mask for beginners. While they have been promoted for their ease-of-use over conventional masks and snorkel tubes, there is a growing concern over the safety of full face snorkel masks.
A full face snorkel mask has a large viewing window and an integrated snorkel tube with float valve to prevent water from coming down. Inside the unusually large mask, there is a breathing cup that covers the nose and mouth allowing a more natural breathing experience. The mask hooks under the chin to cover the entire face and uses tight fitting straps criss-crossing the back of the head to keep it secure.
The first manufacturers to market did extensive research and development for the production of their full face snorkel masks. These masks are typically priced from $75 to $125 USD. Since the introduction, there have been dozens of copycat masks from relatively unknown companies with little documented testing and they are pricing their masks from $25 to $75.
Since mid-2017, there has been a controversy brewing in regards to the safety of full-face snorkel masks. Some regions are reporting higher than average snorkeling-related deaths and are now studying potential correlations with the usage of full face snorkel masks. Some local government officials are requesting national government research on the safety of individual mask models relative to standards.
The primary safety concern is the potential for carbon dioxide buildup within the mask. While all snorkel tubes have a deadspace where exhaled air stagnates and must be cleared by the snorkeler before they get to the fresh air above, there is concern that full face masks have a larger deadspace resulting in more carbon dioxide rebreathing. The consistent rebreathing of deadspace carbon dioxide buildup can result in disorientation or loss of consciousness due to negative pulmonary edema. Negative pulmonary edema occurs when a snorkeler is overbreathing within the mask/snorkel which results in fluid to leak into the alveoli within the lungs. The symptoms of pulmonary edema include shortness of breath, crackling or rattling sound in the lungs, and coughing up blood-tinged sputum (hemoptysis). In addition to the deadspace issues, the airflow resistance of full face masks, as well as snorkel tubes, can lead to Rapid Onset Pulmonary Edema. The resistance to inhalation creates a negative lung pressure where, again, fluid can leak into the lungs.
Within the dive equipment industry, all breathing regulators and tubes should comply with the breathing resistance standard known as EN250 (either EN250:2014 or EN250A). Breathing resistance can be limited by tube length, tube diameter or the float valve sticking at the end of the tube, and the breathing resistance can be magnified by the carbon dioxide in the deadspace. Full face masks can restrict the oxygen intake by either rebreathing excessive carbon dioxide or poorly designed/maintained float valve stoppers. From some studies, many of copycat full face masks exceed the EN250 for carbon dioxide.
Moreover, the effects of a full face snorkel mask can be compounded by Immersion Pulmonary Edema. The research on the cause of Immersion Pulmonary Edema is continuing, but premilinary results point to uncontrolled high blood pressure in swimmers, snorkelers and scuba divers. Either water pressure or cold water can force additional blood from arms and legs back into the body core, which raises blood pressure to the point of forcing fluid to leak from the alveoli into lung space. The symptoms of Immersion Pulmonary Edema include crackling sounds while breathing, shortness of breath, difficulty breathing, fatigue, dizziness, and even coughing up blood.
Since there is a perceived simplicity of full face snorkel masks, they tend to be very popular with inexperienced snorkelers. These beginner snorkelers lack the ability to remain calm during variations in ocean conditions and/or equipment malfunctions.
Therefore, a secondary safety concern is the larger head strap systems of full face masks which can be difficult to quickly remove when a snorkeler panics. The inexperienced users of full face snorkel masks may find emergency removal difficult when their breathing is impaired due to carbon dioxide buildup or float valve stickage, and water intrusion due to leakage.
So, until more safety research is conducted and this controversy is settle, we do not advocate the usage of full face masks.