SDI’s Position on Full-Face Snorkel Masks
Some time ago, the SDI Training and Membership Services team was approached with an interesting question. An instructor was seeking further clarification on whether a full-face snorkel mask would be permitted to be used in an SDI Snorkeling Course. We could give you the easy answer, but a further explanation seems warranted.
In 2014, several manufacturers began releasing variations of the full-face snorkel mask. The masks have gained popularity with end-users for many reasons, one of which is the perceived notion that they are easier to use due to being able to breathe through the user’s nose or mouth. The truth is this is a classic case of a person not knowing what they do not know. So, what does the end user not know?
Issues with Full-face Snorkel Masks
Let’s start with one of the biggest issues first. With many full-face snorkel masks there is a real issue with improper circulation of exhaled gasses, specifically carbon dioxide. Due to the way a mask will fit a user or the total lack of an Oro-nasal cup encompassing the nose and mouth, carbon dioxide can enter the dead space in a full-face snorkel mask. Due to the larger volume in the mask and lack of one-way valves or poor-quality valves, the carbon dioxide ends up building up instead of being circulated back out of the mask. Some manufacturers have worked to try to fix the issue. However, it is still very easy for a user to over breathe even the improved models that have sought to address the carbon dioxide buildup. The other issue is that the improved models typically have a higher cost associated with them. So, end users frequently buy a more cost-effective model.
Full-face Snorkel Masks for Kids
Continuing the same carbon dioxide subject, let’s also look at younger users. The SDI Snorkeling Course allows students as young as 4 to take the course. When assessing the risk to carbon dioxide toxicity or Hypercapnia as it is also known, children have lower tidal volumes in their lungs than adults. This means that children have less ability to move air than a full-grown adult would, and it also means that there is a higher percentage of air space inside the mask compared to their lung volume. So, a child is at a greater risk of carbon dioxide toxicity than an adult would be. Records being kept by the Hawaii state health department showed that fatalities had nearly doubled in 2018 with the primary theory being related to complications with full face snorkeling masks. It was even reported that 9 snorkeling fatalities occurred within a 4-week period in Maui alone. In each case the users were wearing full-face snorkeling masks. The health department has not gone so far as to say that the deaths are related to the use of the mask or if the deaths can be attributed to the fact that there are just more people now using this type of mask.
Clearing a Full-face Snorkel Mask
Next, let’s discuss clearing a full-face snorkel mask. With a normal half-mask and snorkel, the individual components may need to be cleared out due to water entering them. This may mean that the user must clear water out of the mask or clear water from the snorkel. In either case, a little practice will normally have the user efficiently clearing water from either piece of equipment. However, due to the large volume of the full-face snorkel mask, it is very difficult to remove all the water from the mask using the normal methods of clearing. In most cases the user will end up just removing the mask and emptying the water out that way. This will not lead to a good experience for the user if they have a poorly sealing mask due to low quality materials being used in the skirt of the mask such as the PVC skirts seen in many of the lower cost masks instead of silicone in the higher cost models.
Equalizing with a Full-face Snorkel Mask
Finally, let’s discuss equalizing at depth. Even though SDI encourages snorkelers to seek further training for extended breath holds by signing up for the PFI Basic Freediver or the PFI Freediving course, snorkelers still enjoy leaving the surface briefly to get a better look at something underwater. With the lack of a nose block in a full-face snorkel mask, it is virtually impossible to be able to pinch off your nose so that you can use the Valsalva technique to equalize. Many masks have floating valves that are designed to close off the snorkel so that water can’t get in when diving, but the user will still be very limited in their dive if they cannot equalize.
Our Decision on Full-face Snorkel Masks
With all of that said, the SDI Snorkeler course has a few considerations to keep in mind. For the required equipment, the standard says, “Basic snorkeling equipment; mask, snorkel and fins” The commas would imply that the mask and snorkel are separate pieces of equipment and based off the previous information in this article, you can see why. Also, there is a requirement that the student must be able to perform “proper breathing and clearing of a snorkel”. Having to remove the entire mask in order to empty it of water would not meet the intent of the skill performance. Due to all of the reasons that have been discussed, full-face mask snorkels should not be used during SDI Snorkeler courses.