How Does a Snorkel Work?

At some point in our lives, we’ve probably all bought one of those cheap snorkel sets from a beachside shop. They usually consist of an eye mask and a breathing tube. 

With your trusty snorkel, you’ll no doubt have spent the day laying face down in the sea marveling at the creatures and underwater seascapes beneath you. Let’s face it, you probably left the beach with a cracking sunburn and a lot of salt at the back of your throat and in your eyes! 

The thing about cheap snorkels is that they aren’t the most reliable bit of kit. They do, in the most basic sense, do what a snorkel is supposed to do.

However, they also tend to leak profusely at the slightest wave. 

So let’s take a look at what snorkeling gear, that is decent snorkeling gear, should do. 

The Parts

In the simplest sense, a snorkel consists of a mask and a tube. There are lots of different designs of these two simple parts but they perform the same function across all designs. 

We’ll take a look at the function of each part in a second but first, let’s look at the bits and pieces of each part. 

The Mask

The mask is made up of a frame that goes around your eyes. This bit is hard plastic which gives the mask its shape. The frame is surrounded by a skirt that creates a seal. The job of the skirt is to keep water out of the mask.

Masks are held in place with a strap. This strap tends to be rubber and is adjustable on both sides of the mask or at the back of the head. A quality strap is important for helping create a tight seal. 

A tight seal not only stops seawater from getting in your eyes but it stops the lenses from fogging up. You don’t want to ruin your underwater view with fog. It’s a pain in the butt to clear when you’re in the water. 

The final part of the mask is the nose pocket. Unlike normal goggles, a snorkel mask covers your nose. This is because you need to breathe through your mouth and not your nose! It can take a bit of getting used to, we admit. 

The Snorkel

The tube part is the actual snorkel. In olden times, snorkels were made from reeds or bamboo that were hollowed out. Nowadays, snorkels are made of plastic. 

The snorkel has a mouthpiece which, surprise, surprise, goes in your mouth. It usually has two prongs that you can bite onto for a better grip if needed. 

The mouthpiece is connected to the tube with an elbow joint. In higher-end snorkels, there is usually a flexi-tube between the mouthpiece and the hard tube. This allows you to fit the snorkel more comfortably. 

The snorkel attaches to the mask with a small clip. This clip helps keep the snorkel upright when you’re swimming. After all, a snorkel is useless if the top isn’t above water. 

Depending on the type of snorkel, you may also notice a purge valve and a guard on the snorkel. More on these in a second. 

What is the Point of a Snorkel? 

The point of a snorkel is to give you a constant supply of fresh air while you swim. It’s a pretty important function if you value being able to breathe…

The snorkel top sits above the water allowing you to breathe air through the mouthpiece under the water. 

The mask allows you to see underwater without hurting your eyes. It also stops you from breathing through your nose which would be useless underwater. 

Snorkeling is not like diving. You don’t carry a supply of oxygen with you so you can’t breathe beneath the water. A snorkel is designed to deliver oxygen from the surface to your lungs. 

The length of your snorkel will determine how deep you can go. Most snorkels are about 10 inches long. The longest possible length of a snorkel is 16 inches. If snorkels were any longer they would be unwieldy. 

Another issue with long snorkels is that they would be nearly impossible to breathe through. The deeper you go the higher the pressure around you. You’d need some considerable lung power to breathe through a snorkel of about 2 feet. Power you just don’t have because the pressure makes it harder to inflate your lungs. 

The final reason snorkels are so short is down to dead air. When you breathe out your body gets rid of carbon dioxide. Again you need a bit of power to get rid of all the carbon dioxide from your body. 

If you have to push that gas through a long tube you need even more power. If you can’t clear the tube of carbon dioxide then the next breath you take will be mostly carbon dioxide rather than oxygen.

Wet Vs Dry Snorkels

Remember the valves and guards we mentioned? Well, this is where they come into play. 

Sometimes when snorkeling, you’ll see something that you just have to take a closer look at. To do this you’ll need to dive below the surface. 

Wet snorkels are the simplest kind of snorkel. The cheap ones you buy for the beach are almost always wet snorkels. When dipped below the surface water will fill the tube. This isn’t an issue as long as you remember to hold your breath. 

When you come back to the surface you’ll need to empty the tube of water. Usually, this means giving it a good blow and potentially tipping the tube. It’s pretty annoying. 

The other issue with wet snorkels is that a decent-sized wave can put water in your tube and into your mouth. 

To combat this, semi-dry snorkels were invented. These snorkels have a splash guard at the top of the tube. The guard is usually slanted to direct water away from the tube. These snorkels will still fill with water when submerged. 

A dry snorkel has a float valve within the splash guard. When on the surface, this valve is open allowing air into the tube. The splash guard keeps water out as it does on a semi-dry snorkel. 

When you dive below the surface the floatation valve floats to the top of the tube. This seals the tube and stops water from getting in. When you rise to the top again the valve drops down again. 

Dry snorkels and semi-dry snorkels usually have a purge valve on the elbow joint near the mouthpiece. The purge valve can be squeezed to allow you to blow any water out of the bottom of the snorkel. This requires much less lung power than trying to get the water out of the top. 

Final Thoughts

As you can see, there’s a lot of technology and design in those simple, innocuous snorkels. They are vital to divers and snorkelers, a literal lifeline. 

The purpose of a snorkel is to allow you to breathe while you watch the underwater world below you. Even the cheapest beach toy version is usually capable of this task. 

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