Research Update: Full Face Snorkel Masks

In the past five years, full face snorkel masks (FFSMs) have exploded in popularity. At first these products were made by a small number of reputable manufacturers, but there is now a broad spectrum of designs of varying quality and no regulation of testing or function. Despite their prevalence, few formal studies have assessed these devices. In this webinar, scientists from the Duke University Center for Hyperbaric Medicine & Environmental Physiology will present their recent experimental work assessing a selection of FFSMs. This work concluded that many FFSMs do not work as advertised and some have design features that may even increase risk to the snorkeler.

[@timkenyon6088]

Respectfully, you missed the smoking gun(s). I am an experienced scuba diver, free diver and (obviously) snorkeler. I have witnessed first-hand problems with the full-faced masks. #1 - when a snorkeler has a problem with water in the snorkel (as in from a wave or an inadvertent shallow dive), a traditional snorkel is just spit out and the person rises above the water and breathes. Takes all of 1 second and is very reflexive. They do not take off the mask. When the full-face user gets water in the mask via valve malfunction (wave goes over or the person inadvertently dives and the water ingress valve does not function completely) or because the mask does not fit sufficiently, the person reflexively sticks their face above the water and tries to breathe, sucks water, struggles getting the mask off and might have a very serious outcome. I have seen this happen first-hand. Thus, your mask-doffing time comparisons are invalid. Again, the traditional snorkeler does not take his mask off, he just spits out the snorkel, sticks his head above the water, and breathes.
#2 - Another point is tidal volume - the volume of air contained within the equipment. You can quantify this by direct measurement, but by observation, the amount of air in a traditional snorkel is significantly less than the full-faced mask. When breathing shallowly with inadequate in/out differentiation as you showed, the full faced used breathes much of the same air over and over, increasing CO2 and decreasing O2. This is minimized in the traditional snorkel because of the lower resistance to breathing and, primarily, because of the low volume of air in the traditional snorkel.
Last point - when the full-faced user tries to breathe in and gets water, the larynx/pharynx spasms shut. This has happened to me and was terrifying the first time (really, every time). This causes panic and complicates getting the full-faced mask off and recovering. This is not as prevalent with the traditional snorkel because of the ease in recovery (the spit it out method).
PS - I tried a full-faced mask once just to see what it was like. It scared the hell out of me, and I have been doing this a long time. I have taught snorkeling to many, many Boy Scouts and have prohibited use of full-faced masks.
I look forward to your reply and very much appreciate the rigor of your work.

[@brianmccallister2981]

I have always been hesitant of these masks. This just reaffirmed my thoughts.

[@TheBlackClaymore]

Thank you for conducting the study. Your work has provided some insight into the workings of the masks. Understandably people will have opinions on the masks that may or may not be based on facts. Science and proper research based design is essential for safety. As a generalization, when you buy the lowest price it doesn't mean you get the best deal.

[@RobSharkRescue]

Sorry, couldn't hear in the webinar - how long were the subjects asked to use the snorkelling equipment before air measurements were taken?

[@DiversAlertNetworkTV]

Hi @Robin Fewster - thanks for the question. The subjects were asked to snorkel at a consistent rate of pedaling for at least five minutes before we started using the data. We then had them keep pedaling for at least one more full minute of data collection.

[@RobSharkRescue]

Thanks, maybe when snorkelling for 20-30 minutes more CO2 would accumulate?

[@joselysylva9455]

Bom dia
SEGURANÇA NO MERGULHO GENTE

[@joselysylva9455]

Por fim, seu pai, Isaque, lhe disse:
“Você viverá longe das riquezas da terra
e longe do orvalho do alto céu.
40 Viverá por sua espada
e servirá a seu irmão.
Quando, porém, conseguir se libertar,
sacudirá do pescoço esse jugo”.

[@fiqihalkaromah]

Buffering always

[@Len_M.]

I went tubing in a lake by sand point, ID and I couldn’t believe the water temp it was like being in a bath tub… definitely not used to that living in Canada and going swimming/Tubing/sea-dooing, Lakes are Cold up here… I’m thinking about getting a Dry suit and other scuba gear, eventually a CCR.. I was going to get certified a few years ago, but that was foiled due to the relationship with the person that was joining me. 🫤