Usnork Full Face Snorkel Mask, Easy-Breath Snorkeling Gear, Anti-Fog and Anti-Leak Snorkel Set with Exceptional Panoramic View, Waterproof Phone Bag and Towel Included (Red-Black, S/M)

The concept is brilliant but the execution is flawed. On the inhale cycle air enters the snorkel, flows through the face area and through check valves to the nose/mouth compartment where it is inhaled. When you exhale the air is supposed to exit through the check valve at the bottom of the mask. However, this does not always happen. Due to poor seal around the nose and flex in the membrane where the intake check valves are located the air will exhaust back through the same path that the intake air came through. This will cause a lot of the spent air, now higher in CO2 to be trapped inside the mask and subsequently rebreathed creating an asphyxiation hazard, especially if you are a shallow breather. Many reviews state that ‘the mask passages are too small restricting breathing’ or something similar. I suspect that those users are experiencing this condition. Another indication is the mask fogging up. Spent air is much higher in water content and will cause condensation when contacting a cool surface. If you experience either of these conditions you should discontinue use immediately. You can easily check to see if you will experience this by removing the snorkel and donning the mask. Breathe as you would but place your hand above the opening for the snorkel. When you exhale you should not feel any air coming from the opening. If you do feel air it indicates that spent air is flowing back through the intake rather than out the exit at the base. If this is the case you should not use the mask. A regular snorkel will also cause you to breathe a small amount of spent air again but the air volume of this mask is much greater than the barrel of a regular snorkel and that is why this becomes a problem.

I was just in Mexico, Maya Riviera, and snorkeled with my new mask. I have always had fit issues with other types of snorkeling masks due to the shape of my face. I had absolutely no fit problems with the Usnork full face snorkel mask! I put it on, tightened it and that was it! A bonus was the larger view and no fogging, plus the price is very reasonable! I love this mask and would highly recommend it to anyone who has fit issues with standard face masks.

Great concept - will never snorkel without it. Careful though, the plastic scratches easily.

good concept - fogged easily

Leaked a little in the middle of the forehead, used a little Vaseline which took care of the problem.