A full face snorkel mask at Smith's Reef on Providenciales, Turks and Caicos.
Full face snorkel masks have become popular over the last few years, yet there are many safety and general experience issues that snorkelers should be aware of.
One observation that should be considered is that an almost non-existent percentage of experienced and dedicated snorkelers use full face masks. Simply put, enthusiasts that know and spend time in the water do not choose full face masks.
Full face masks unfortunately tend to appeal to beginning snorkelers, whom also tend to be less able than proficient snorkelers to recognize and respond to the many potential problems that may occur.
In recent years, many dive shops (primarily in Hawaii) have stopped renting and selling full face masks due to safety concerns.
Safety Concerns and Other Considerations
CO2 Build Up
The primary and overriding concern with full face masks is C02 build up in the mask. Humans exhale carbon dioxide (CO2) when they breathe, and this CO2 can collect in the voids inside the mask when being used in the water. When CO2 levels increase in the mask, users may experience headaches, panic, dizziness, and unconsciousness, which of course can be life threatening when experienced in the water!
A snorkeler with a full face snorkel at Leeward Reef in the Turks and Caicos.
Due to the large volume of space in the mask, the typical human lungs are unable to circulate all air through the mask and prevent CO2 from accumulating. In contrast, a traditional snorkel only has a smaller breathing tube with much lower volume, which is consequently easier to purge.
Some full face mask manufacturers state that their masks are not intended for “exercise”, yet any snorkeler entering the ocean should understand that there’s a reasonable chance of strenuous activity.
Some full face masks have one way valves between some of the chambers and spaces in the mask, which do help to facilitate air circulation through the mask, yet such valves may not work correctly, or simply not be sufficient.
Mask fogging, and the user hyperventilating, are two signs that there may be a build up of C02 in the mask.
Unlike nearly all other types of respirators, scuba gear, and breathing masks, there are generally no established standards for full face snorkel masks. Adding to the complexity is the significant number of full face mask manufacturers, all with their different variations which may appear to be minor, yet may cause issues. Just because a certain and good condition variant of a full face mask may not have high levels of CO2 concentration during use doesn’t mean that another that appears similar will work correctly.
Smith's Reef at the island of Providenciales is an excellent snorkelling site.
Another significant problem with full face masks is that it’s extremely difficult for non-proficient snorkelers to clear water or fog from the mask.
Many full face mask makers advertise that their mask won’t fog or leak, yet that’s generally a significant stretch of the truth, and only accurate with a perfectly fitting mask and ideal conditions.
When water does get in a full face mask, you typically have to take the mask off to drain it, and then replace it, which is almost impossible for the casual snorkeler to do in open water. This is difficult due to two reasons: the necessity that one keeps their head fully out of the water during the process, and the fact that full face masks have a tighter fitting and more elaborate strap system, which is harder to get on and off.
With a traditional snorkel mask, it’s much easier to remove and replace the mask in open water, and water and fog can be cleared in the water with the mask on with an easy to learn method.
Wide Angle of View
Freediving the incredible ocean water at West Caicos.
One aspect of a full face mask that may be considered either a pro or con depending on personal preference is the wider angle of view over traditional snorkel masks. Generally, the wider angle of view sounds like a good thing, yet it’s actually harder to see the smaller animals and details, as the dome that surrounds the user’s face effectively deceases magnification by about a third.
Difficulty of Diving
Most beginning and causal snorkelers won’t initially care, yet another negative is that it’s not feasible to dive down or freedive while wearing a full face mask due to the near impossibility of equalising the volume in the mask as one descends.
As water depth increases, pressure likewise increases, and it’s necessary to equalise the air in the sinus cavity and in the mask to avoid discomfort and possible sinus or ear damage. With traditional snorkel masks, this is easy to do because of low volume of air trapped in the mask. With a full face mask, there’s too much volume in the mask, and snorkelers are likewise unable to pinch their nostrils to aid in equalising the sinus cavity, which is a common technique with traditional masks.
The mask selection at the Dive Provo shop on Providenciales. Getting the right gear for you doesn't mean that it has to be the most expensive, but it should fit you properly.
Snorkel belts or vests should be worn when snorkelling, especially by beginning snorkelers and those who may not be physically fit. Such flotation devices provide additional buoyancy, and help snorkelers to float, which makes it much easier to clear and refit masks when in the ocean.
There’s a wide selection of full face masks available for sale. Some of the advocates of the masks from the original developers such as Tribord and Ocean Reef claim that these originals have been extensively tested, and likewise claim that the less expensive and more recent additions on the market from some other competitors don’t have the necessary testing and product details that ensure that CO2 doesn't accumulate.
What to Look For in a Snorkel Mask
Standard snorkelling equipment compared to free diving gear.
Finding the right snorkel equipment is essential to having a fun, safe, and comfortable underwater experience.
The most critical aspect is proper fitment. Most persons will not be best served by purchasing one of the blister pack snorkel sets (often “one size fits all”, that are too large for most) that are common at the larger grocery and retail stores.
Generally, it’s best to visit a dive or water sports shop that maintains a selection of masks, snorkels, and fins, and has someone who can advise on fitment. Masks should seal well enough that they could be used without a strap, and snorkel tubes should be roughly matched to the user’s size to ensure that CO2 doesn’t build up in the tube.
If it’s not a viable option to visit a dive shop before purchasing, and alternative is to purchase from one of the online dive-centric stores, such as LeisurePro. Selecting equipment that’s about the right size and has good reviews increases the chance that everything will function right.
Proper fins also make a big difference. The fins included in most kits are too small, and typically not rigid enough for their size.