Understanding Your Dry Snorkel

HISTORY OF DRY SNORKELS

Dry Snorkels are not really new to the world of snorkeling. If you are old enough, you might remember a dry apparatus that, rather than being attached to the mask strap, it was integrated into the mask itself. It was the Nautilus Twin Snorkel Mask. The two snorkels protruded from the upper corners of the mask perpendicular to the viewing face plate. The dry feature consisted of two birdcage like holders that housed ping pong balls. When submerged, the ping pong balls would float up to seal the air inlet portions of the breathing barrels. While this was good in theory, several factors came into play that made this a mask one to avoid rather than to use.

One of the factors was Boyle's Law of Physics which refers to pressure and volume relationships of gasses. The ping pong ball is a shell with an internal air space. As external pressure (in this case, pressure exerted by the weight of the water) is added to the shell, the gas on the inside would compress. If enough pressure were exerted, the ping pong ball would crush allowing water to enter, flooding the entire mask. Snorkels that were independent from the mask used the same dry style birdcage and ping pong ball design quickly fell into disfavor and the dry concept fell to the wayside for 20 plus years.

TODAYS DRY SNORKELS

The Total Dry design (picture to the right) resurfaced again in the 1990's with heavy, clunky styles that eventually evolved into the sleek and efficient models that are seen today. Since their reintroduction, they have fast become the preferred snorkel of enthusiasts worldwide. The purpose of the "dry" design is to keep water from entering the breathing tube while the snorkel is in active use. This is achieved by the top of the snorkel itself. It works varying with each manufacturer but the principle is the same.

When the top of the snorkel goes below the waterline, the mechanism will seal the breathing tube to prevent water from entering. When the top of the snorkel returns above the waterline, it opens again allowing air to move freely. Some manufacturers use a float/pivot or a float/ball design but the principle is still the same.The mechanism will also have a plastic shroud around it which acts as a water deflector or splash guard. It is meant to keep water from entering (from spray or splashing) while the top of the tube is above the waterline and the snorkel is actively being used.

Having a dry snorkel does not mean that there will never, ever be water in your snorkel. If you were to take the mouthpiece out and allow it to go below the waterline, there is nothing to stop water entering through there. Fear not because manufacturers did take this into account by adding a one way "purge" valve at the base of the snorkel which will allow you to expel the water. All it takes is one or two short, sharp exhalations and the water is out. Water may also enter if there is sand, grit or salt deposits in or around the dry mechanism area or the purge valve. A proper cleaning and rinsing of the snorkel usually enough to prevent that.

Some dry snorkels like the Scuba Max Neu Air have some added additional features. This snorkel still has the dry top and the purge valve system but every exhalation is directed out of the purge valve rather than going out of the top of the snorkel. The reasoning behind this feature is that you get fresh air with every inhalation rather than rebreathing carbon dioxide that you just exhaled. This is relatively a newer concept in snorkel design but expect to see other manufacturers coming out with similar designs.

FREE DIVING

Most of our customers are not frequent snorkelers and the dry snorkel keeps water out of your mouth, which is a safety blanket that helps boost your confidence. When free diving, you will notice that when using a dry snorkel and upon resurfacing, the mechanism seems to stick closed briefly. Researching this information led us to Danny Teel of Aqua Lung who offered the following explanation.

"All dry styles have an inherent design quandary that is usually only experienced by the high skilled water lovers, or so it use to be. Those experienced do not use submersible models since they can be challenging when diving to depths greater than most recreational snorkels venture to. When it is taken to depth, the air in the tube is compressed. This creates a vacuum which seals the tube to prevent water from entering the barrel to fill the void. This vacuum affect can draw in the users lips or tongue. There are tricks to resolve this.

If you are not familiar with using this technology, you may absorb in your lungs some of the original volume of air from the tube. This will cause the tube not to fully equalize upon returning to the surface and therefore the vacuum affect is still engaging the Dry-Top seal. I too, dive down to depths of up to 35’ and have done so with our entire submersible dry collection. I have learned how to manage my lung capacity so as not to further add to the vacuum affect, therefore the top opens fine upon surfacing.

Tip; when you hold your breath for 30 seconds or more you desperately need air. Upon surfacing instead of an immediate inhalation of fresh air you must first exhale the old air. This will resolve the vacuum affect if done at the surface."

The reintroduction of the dry model to the snorkeling world was a long time coming but well worth the wait. Special thanks to Dan Teel from Aqua Lung for his valuable and enlightening information. If you are a visual person, above is a short video on how the dry snorkel works.