Full Face Snorkel Mask: Dangerous?

https://www.sfgate.com/bayarea/article/drown-hawaii-bay-area-maui-full-face-snorkel-mask-12547806.php

There is still some speculation, but there may be reason to be wary of full-face snorkel masks.

With a traditional snorkel, you breathe in and out through the tube. As you exhale, you fill the tube with the air leaving your lungs. Then, when you begin to inhale, you inhale one snorkelful of that same air you just exhaled. But as you continue to inhale, you will be drawing fresh air in through the top of the snorkel down into your lungs.

As long as the snorkel is relatively small, this isn't a problem. Your lungs are so much bigger than the snorkel that the amount of re-breathed air is negligible. You're getting almost completely fresh air.

A full face snorkel uses a different method for making sure that you're not rebreathing your own exhaled air. Because the volume of the mask around your face is much larger than the volume of a traditional snorkel, the full face snorkel mask has a series of one-way mechanical valves, and separate paths for inhaling versus exhaling. But those valves are possible points of failure. If they fail to operate properly, you may start exhaling air into the space that you'll be inhaling from. Then you'll be re-breathing your own carbon dioxide, instead of drawing in fresh air with each breath.

My suggestion would be, at the very least, if you're considering a full face snorkel mask, get a very high quality one, and carefully maintain it according to instructions. Don't let sand get near the valves. And use a buoyancy vest, swimming within your limits so that, if the mask isn't working perfectly, you will be very safe ditching the mask and swimming without it. And follow all the other normal water safety advice, such as being with a buddy, etc.

But personally, I'm not going to touch one of those full-face snorkel masks.

I'm a certified SCUBA diver with over 70 open water dives under my dive belt, and a bunch of snorkeling experience that I haven't kept track of. I use a traditional low-volume mask, and a separate snorkel, with no valves or other moving parts.

The first lesson in my SCUBA diving class was how to use the mask. And the first thing they taught us was how to take the mask completely off, put it back on, and clear the water from it, while we were in water over our head. The second week's lesson added the snorkel, and again, we learned to take it off, put it on, and clear it while in the water (hint: if you stay in normal face-down position and try to blow the water out, it takes a LOT of effort, because you're pushing the water up. But if you look to the sky, pointing your snorkel down, a gentle breath as you reach the surface is all it takes to clear the snorkel.)

Another tip: The way to check the fit of a mask is to put it on your face, without the strap, then inhale through your nose, and let go of the mask. If you can suck it onto your face just by inhaling, and keep it attached to your face as you move your face around, then it's sealing pretty well and it fits you. If there are leaks around the edges, the vacuum seal will be broken, and the mask will fall off your face. That mask didn't fit you. This method of testing a mask fit won't work with full-face snorkel masks, though.

If you can get a local dive shop to give you snorkeling lessons before you go snorkeling on a trip, I encourage you to do so.

Interesting - though a real shame the reporter said "carbon monoxide" instead of carbon dioxide in the video.

Interesting - though a real shame the reporter said "carbon monoxide" instead of carbon dioxide in the video.

Yes, that grated on my ears, too. It was absolutely wrong, but then, we all knew what she meant. I've heard worse from journalists.

Hi....we wrote a pretty indepth safety post for using full face snorkel masks here. We couldn't agree more. It's a matter of using a quality full face mask, maintaining it, and knowing how it's supposed to work. Try getting used to the mask first so that when something isn't quite right, you'll know.

-Ken

Owner: SnorkelStore.net

Like everything else in this world different people have different needs. Many people find traditional masks and snorkels very uncomfortable to use. For them, a full face mask might be the answer they are looking for.

As for the safety aspect, I looked into this very thoroughly when it was brought up before. I can find no evidence that they are unsafe. In fact the only thing I can find is speculation by a grieving husband who's 70 year old wife went snorkeling alone in the ocean in a no swimming zone in Hawaii and died. He is looking for answers and for someone or something to blame.

As for carbon dioxide poisoning. Do some research and you will see that that claim is laughable in snorkeling situation.

Full face masks aren't for everyone but it would be wrong to dismiss them out of hand because of pure speculation and junk science.