Snorkeling is a very popular recreational activity especially in warm waters around tropical islands. It allows you to explore the underwater world while remaining on the surface! It is very accessible to anyone with little equipment and no required training. Grabbing a snorkel, mask, and fins is the easiest way to explore coral reefs. But how does a snorkel work?

Marine Science Teacher, Anna Ortega on-site in South Caicos
Anna Ortega snorkeling on a conch survey in the Marine Protected Area off of South Caicos. Photo / Anna Ortega

How Does a Snorkel Work?

A snorkel works by letting a person breathe without lifting their head out of the water when swimming face down. Snorkels are accompanied by masks, which allow the person to see and breathe.

There are several types of snorkels. The most basic models are made from rubber or plastic, shaped into a slightly bent tube with a rubber or silicone mouthpiece attached to one end. They are typically about 1 foot or 30 cm long.

ZIPOUTE Snorkel Mask Full Face

Scubapro Escape Semi-Dry Snorkel

Bairuifu Freediving Snorkel

The snorkeler first attaches the snorkel to a mask with a snorkel release or holder. You will want to get the snorkel release or holder in a good position and ensure it doesn’t get entangled in your hair. Once the snorkel and mask are attached, the snorkeler swims on top of the surface and is able to breathe through the tube (snorkel) in order to observe the reef without having to lift their head to breathe all the time.

Why Can’t We Snorkel Underwater?

You may wonder why snorkels are not extremely long in length (which in theory would allow us to go deeper but still breathe at the surface). This is because the water pressure increases greatly and even at shallow depths the pressure will not allow your lungs to “pull” the air to depth. It is impossible past a certain depth.

Read More: Boyle’s Law in Scuba Diving. Understanding Pressure and Volume.

Furthermore, even a regular-sized snorkel traps Carbon Dioxide (CO2). CO2 trapped in a snorkel is called dead-air space. If you inhale CO2 before the fresh air from the snorkel, it can lead to an air starved feeling and shortness of breath in extreme cases.

Traditional Snorkels

The most commonly used snorkels are traditional types. They are very cheap, easy to use and low volume. Basically, how this snorkel works is by placing one end of the tube in your mouth, and having the other end sticking out and sucking in air from the surface.

Most traditional snorkels are composed of a tube and a mouthpiece. They are light-weight and often made of a rubber or silicone material, making them flexible for easy storing. Scuba divers also use snorkels on the surface and often prefer traditional, low impact and light weights snorkels. Freedivers also prefer traditional snorkels since the sport of freediving is all about reducing the amount of equipment and equipment dependence.

Bairuifu Freediving Snorkel

Mares Dual Snorkel

These snorkels require the snorkeler to constantly manage their airway. Often water manages to get into the tube which needs to be cleared. After a breath-hold dive, the snorkeler needs to preserve enough air in order to clear the snorkel on the surface. The tube fills with water upon submersion and the forceful exhale on the surface blasts that water out of the tube.

This requires skill and practice.

Read More: Learn How to Breath-Hold with a Freediving Coach

Dry & Semi-Dry Snorkels

Dry snorkels feature newer technology built into the snorkel. They typically feature a drain valve situated at the bottom of the mouthpiece. This is a one-way valve, allowing air and water to escape, however no water to enter. This means that airway control is simpler compared to traditional snorkels. The small amount of water that accumulates with ill-fitted mouthpieces can exit the snorkel via the drain valve without the snorkeler having to constantly blow it out.

TUSA Hyperdry Elite II Snorkel

Cressi Foldable Adult Dry Snorkel

Furthermore, they often feature a splash guard (semi-dry) or ball valve (dry) at the end of the tube. A splash guard simply prevents most of the water from small waves to enter the tube and fill the snorkel. Whereas a dry snorkel prevents water from entering the tube altogether, even when fully submerged. Once you resurface with a dry snorkel, the valve allows air to flow both ways again. Some newer models allow exhaled air to escape the snorkel each time, reducing the amount of CO2 inhaled each time.

Read More: How To Snorkel Effectively

Even a “dry snorkel” however is no guarantee that no water will enter the snorkel. Ill-fitted mouthpieces or a peculiar angle can still allow some water to enter. For beginners, these snorkels make snorkeling much easier. Many people give up on snorkeling because they do not know how to manage their airway effectively and are sick of breathing in lots of saltwater.

Full Face Snorkel Masks

Relatively new on the market are snorkel masks. These seal around the person’s face, allowing easy and continuous breathing through their mouth and nose. Full-face snorkeling masks keep the airways separate to prevent the mask from fogging up. The snorkel component on top is a dry snorkel design in order to prevent flooding of the full face mask.

WSTOO Snorkel Mask

Greatever G2 Snorkel Mask

Beginners are less likely to perform breath-hold dives (where you hold your breath and dive underwater completely). This is why full-face snorkel masks are very popular among beginners.

It is quite difficult to dive down with the large air pocket trapped near the snorkeler’s face. They do however keep water away from a snorkeler’s airways, which increases comfort for inexperienced ocean explorers. A regular snorkel with a mouthpiece can sometimes be uncomfortable for new snorkelers, so a full-face snorkel mask can be much more relaxing.

Snorkeling and Safety

Snorkeling seems so easy and safe. But is it? When asking how does a snorkel work, let’s consider that it is essentially a tube that you breathe through. A snorkel’s technology does not prevent drowning. This means that proper training and skill can greatly increase the effectiveness and safety of a snorkel.

Snorkeling can be dangerous in certain circumstances; rough water conditions, inability to swim, unfamiliarity with the equipment etc. Similar to scuba diving and free diving, snorkelers must also set personal limits. More experienced snorkelers or divers should always accompany a new and inexperienced snorkeler. It is many people’s first entry into the underwater world and it should be an enjoyable one.

Read More: Our Top Snorkeling Tips for Beginners


How does a snorkel work? Well, it really depends on what type of snorkel you use. However, they all provide air through a tube that is inhaled via the mouth. Snorkeling is often a gateway experience to scuba diving and free diving. In fact, it requires a decent amount of skill to do well, especially when duck diving down in order to get closer to the reef. Snorkels are a wonderful and easy way to start exploring the ocean.

Read More: What to Wear Snorkeling for Fun, Comfort, and Safety!