How does a Snorkel Work Underwater? Dry & Semi-Dry Snorkel Guide+Best Review

If you’ve plans to visit the underwater world, by snorkeling, scuba diving, or free-diving, chances are you will need a snorkel. It is your best friend when your face is below the water’s surface as it allows you to breathe without lifting your head. They come in different designs including wet, semi-dry, and dry.

But as invaluable as a snorkel is, seasoned snorkelers and freedivers can go below the surface of the water without it. The following are more details on how it works, the types plus the best brands with a buying guide.

How Does a Snorkel Work?

A snorkel is a “J” or “L” shaped tube that allows you to comfortably breathe air from above the water’s surface when your nose and mouth are submerged.

How it works, you simply attach it to your mask then place the lower end (mouthpiece) of the tube in your mouth. Once your nose and mouth are submerged in water, adjust the position of the snorkel in a way that the top end of the tube is always above the surface of the water.

While you head is in water, the mouthpiece properly held within your mouth, the snorkel will let you easily breathe in and out through your mouth while you enjoy the scenery under the water.

How does it work underwater?

You’ve probably seen divers with snorkels deep under the sea. Do snorkels make it possible to breathe deep down underwater? The quick answer is No!

Once the whole device is submerged, you cannot breathe. It has no section to store fresh air for you to breathe. The divers have special breath-holding abilities that make it possible for them to stay underwater for a while.

Point is divers, use these devices differently but it still does not change their primary function which, as you already know, is breathing with ease while floating near the surface of the water.

Dry, Semi-Dry & Wet Snorkel Types + Parts.

The types of snorkels known today include wet, semi-dry, and dry snorkel.

All of these types come with the basic parts that make up a snorkel: the main tube/pipe, a mouthpiece and a means to attach to a mask. Other parts include a float valve, splash guard, and flex tube.

Parts of a snorkel diagram

Generally speaking, they all serve the same role, but there are a few minor differences in terms of design and additional features.

Knowing the types and differences can help in making the right choice when shopping for a snorkel. The more knowledge you have, the safer you are and the better your snorkeling experience will be. Let’s take a better look at our 3 main types, how they work, and their differences.

Further Reading: How to Snorkel: A Beginner Guide & Pro Snorkeling Tips

Dry Snorkel

First up is the dry snorkel, which has become quite popular these days. Let’s start with why it is called “dry”. The answer is pretty simple. Do you know how traditional snorkels usually allow water to fill in when you submerge?

Well, dry snorkels don’t. They have a float valve on the top of the tube that opens and closes to control to flow of air and water into the snorkel. It is the same technology used in modern full-face snorkel masks.

The dry snorkel float mechanism involves special floating balls that rise up to seal the airway once the snorkel is submerged. This ensures no water gets into the tube.

When the snorkel is at the surface, the balls are lowered to open the airway. This allows you to breathe without having to clear water.

How exactly the dry valves work may vary depending on a brand or model but they basically open and close the airway.

These types of snorkels are best for beginners or users who want to swim just on the surface of the water.

Other comfort features that improve the functionality of a modern dry snorkel include;

Splash Guard

 It is a plastic material that sits over the snorkel top opening. Its role is to prevent water and wave spray from getting into the snorkel tube. It only works when the snorkel is not submerged. It is important especially if you are snorkeling in areas where the water is not calm.

Purge Valve

It is the bottom part under the mouthpiece where water flowing down the snorkel collects. Usually not gallons but small amounts. When you blow air into the snorkel, the valve opens and the water is forced out.

Flexible Tube

This a flexible piece of pipe where the snorkel bends: the section between the strap attachment point and the mouthpiece.

A flex allows you to adjust the mouthpiece position for a proper and comfortable fit. So, if you have a rare-shaped head or face, which is yet to be featured in the Guinnesse World Records, you do not need to worry about a snorkel that will match your shape. A flex tube works for all.

But there is a catch. As fancy as a dry snorkel is, it limits your underwater activity. It is only useful if you want to float near the water surface and maybe go for a few quick, shallow dives.

But if you plan on going deep, for example, if you want to spearfish or free dive, don’t count on a dry snorkel. The trapped air inside a dry snorkel increases your buoyancy which is something you don’t want if you are trying to go down, not up.

Another problem with dry snorkels is that sometimes, they don’t work properly. If they are not perfectly positioned, water might leak into the tube, which means you could end up inhaling water, instead of air.

Luckily, there are a few snorkels on the market that are specially made to prevent these problems.

Semi-dry Snorkel

Next up is the semi-dry snorkel. As you might have guessed, it is somewhere between a dry and a wet snorkel. Kind of like the best of both worlds.

Unlike dry snorkels, a semi-dry one doesn’t keep ALL the water out. That being said, it still prevents splashing water from entering your tube when you are near the surface.

Rather than a flotation device on the top, you will find that semi-dry snorkels come with several slits and angles that redirect water away from the tube. Once you have completely submerged, it will let the water in.

Most modern semi-dry snorkels come with features similar to those of a dry snorkel. The core distinguishing factor is the dry-top technology

This brings us to a solid question: who can benefit most from a semi-dry snorkel? Well, if you are a scuba diver who wants to save air in the tank while on the surface, but doesn’t want a bulky, buoyant dry snorkel, then a semi-dry is perfect for you.

Wet snorkel

Last, is the wet, regular or traditional snorkel. This one is as simple as it gets. It is basically a tube. To be more specific, it is a “J”-shaped tube that is open at the top.

With this extreme simplicity, you can expect a wet snorkel to let water in whether you are diving or near the surface. So why do people use it? Why do free divers and spear fishermen favor dry snorkels?

Because dry snorkels are very low volume. They have no buoyancy, attachments, or any kind of drag. This allows divers to go as deep as they want on one breath of air.

One thing worth mentioning is that once you resurface, you will have to blast the seawater out of your snorkel to clear it.

Vacationers and first-time snorkelers usually end up swallowing and choking on seawater which can be unpleasant.

Dry vs. Semi-dry vs. Basic (Wet) Snorkels

Now that you know everything about each type of snorkel, here is a comparison table to help you have a better understanding.

 Dry SnorkelSemi-DryWet Snorkel
User LevelBeginner snorkelersIntermediate with some diving skillsAdvanced snorkelers with diving skills
Size & WeightThey are long and wider. The additional weight from the dry, purge valves and Splash guard make them heavier and bulkySlightly lighter and smaller than dry snorkelsLightest, shorter, narrower and less bulky. Easy to carry around
Ease of Use and ComfortEasiest and most comfortable in terms of clearing water and fitEasier than wet snorkels but slightly difficult than dry-tops. It requires clearing.The hardest to use. Rigid tubing can make it a bit uncomfortable You’ll need to blast the water out once you resurface  
EfficiencyMost efficient when swimming near the surface and occasionally making quick, shallow divesOnly efficient at keeping water out while near the surfaceMost efficient when deep underwater (spearfishing and free diving)
SafetyYou won’t have to worry about seawater getting into your tube The added buoyancy from the size and weight increases drag underwater which makes it hard for divers to go deeper. Underwater pressure can collapse the flex tube.  Some have moving splash guard parts that can jam if sand gets inside   Doesn’t keep all the water out  Generally safe, less drag, but requires training before use.  If you forget to exhale forcefully, swallowing or choking on seawater can be unpleasant  
CostMost expensiveMid-range  Most affordable
DesignComplicated and bulkySlight complicated and bulkySimple, minimal, lightweight and more streamlined
Comparing dry, semi-dry and wet snorkel

How to use a Snorkel Properly

You already know what a snorkel is and the types, following is how to use a snorkel.

Using snorkel correctly

Top 5 Best Snorkels

Now that you know everything there is to know about snorkels, you are ready to buy one. To help you make an even better decision, here are some of the best snorkels you can find on the market.

Cressi Supernova Dry

First, cressi is a reputable brand in the water accessories industry. This is a dry-top type of snorkel meaning no water in the tube when submerged.

Cressi Super Nova
Super Nova

It features a flexible lower bore for reduced jaw fatigue
The mouthpiece drops away when not in use a feature that is very useful for scuba divers
High-quality silicone mouthpiece is comfortable and durable
It has a lower purge valve which lets water out quickly.

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Oceanic Ultra Dry Snorkel

Its name pretty much gives away its secret powers. No matter how deep you go, this snorkel literally remains “ultra dry”.

Oceanic Ultra Dry Snorkel

Thanks to its patented dry snorkel technology, water that enters the barrel is pushed back out while air comes and goes easily. Its ergonomic design eliminates resistance and drag while snorkeling.

The Oceanic Ultra Dry is mainly for adults but there’s also an available “mini” snorkel for petite divers.


  • Ergonomic design
  • Remains dry even at depth
  • Has a replaceable 100% liquid silicone rubber mouthpiece with high-density bite tabs
  • Very comfortable
  • Minimal resistance and drag when snorkeling
  • Comes with a “quick-lock” clip to easily attach/detach from your mask
  • Oversized purge valve for easy clearing
  • Available in multiple colors


  • Some people have complained that the float at the top of the snorkel gets jammed quite often

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Speedo Swim Snorkel

Here is yet another impressive snorkel to add to this list. The Speedo comes with a strap that helps maintain the right head position and improve your body alignment in water. You won’t have to worry about your breathing, either.

Speedo snorkel

This lightweight snorkel comes with a flexible mouthpiece and a purge valve for getting rid of unwanted seawater. Feel free to use the Speedo with a mask or goggles. It is fully compatible with either.

The Speedo is mainly for adults but you can also find ones specially made for kids as part of a set (snorkel, fins, and mask).   


  • Unique design
  • The strap helps with body alignment
  • You won’t have to worry about breathing
  • Lets you focus on technique, stability, and positioning
  • Purge valve gets rid of unwanted water
  • Flexible mouthpiece
  • Works with masks and goggles


  • Several customers have complained about a bad odor when unpacking the snorkel
  • Quality and material of the snorkel could be better

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Powerbreather Sport

This throws in the most unique design. Instead of the normal one tube powerbreather comes with two tubes meaning more oxygen from the the top Co2 out from the bottom.

Powerbreather sport snorkel

According to the manufacture, it is built with innovative membrane technology which allows only air in and not water.

It features a drop away smooth bore flex mouthpiece that is made of replaceable 100% liquid silicon.
Unfortunately you cannot do flip turns or laps with this snorkel.

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Cressi Alpha Ultra Dry Snorkel

Cressi is one of the oldest, most popular brands in the world of snorkeling. Whether you plan on diving, snorkeling, or just swimming, you can rely on this Italian company’s elite-quality equipment.

Cress Foldable Alpha Ultra Dry snorkel
Cressi Alpha Ultra

This model is mainly for adults but the company also offers Cressi Kids Junior snorkels.


  • Highly flexible tube
  • Reduces jaw fatigue
  • Easily stored in a BC pocket or travel pack (compact)
  • Purge valve for clearing water
  • Wide elliptical bore shape allows more air in
  • High-quality silicone which is better than PVC
  • Long-lasting
  • Streamlined design (reduces drag)
  • Adjustable clip for attaching it to a mask
  • Drop-away mouthpiece


  • Sometimes makes a whistling sound when you breathe due to the reduced width of the hole along with the flexibility of the silicone tube
  • The bite grip has open areas which make the silicone a bit weak and prone to failure

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Mares Ergo Dry Scuba Diving and Snorkeling Snorkel

Mares is a well known brand. This snorkel features 100% dry top with an exhaust valve and sliding swivel snorkel keeper.

Mares Snorkel

Like the other snorkels in this list, its corrugated hose and comfortable mouthpiece are made out of high quality silicone.

If you want to extent your snorkeling sessions to diving or something like that…this is the perfect snorkel.

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MP Michael Phelps Focus Swim Snorkel

What do you get when you combine an elite swimming equipment company like Aqua Sphere and the most decorated swimmer of all time, Michael Phelps? You get a snorkel that is on a whole new level.

MP focus swim Snorkel
MP Focus

The Focus snorkel is perfect for those who literally want to “focus” on their training, diving, swimming technique, or any underwater activity.

Its unique triangular tube gives it impressive hydrodynamic properties and fits snuggly without any side-to-side movement. With very little drag and utmost comfort, this snorkel is truly one-of-a-kind.

The Focus snorkel comes in two sizes: regular fit and small fit, which might be suitable for kids.


  • Unique design
  • Reduces drag
  • Hydrodynamic properties
  • Increases cardiovascular strength and lung capacity
  • Adjustable lightweight head bracket with cushions
  • Silicone Comfo-Bite mouthpiece (reduces jaw fatigue)
  • One-way purge valve
  • Triangular tube shape prevents side-to-side movement


  • Mouthpiece can be uncomfortable
  • After a few weeks, the snorkel can start to leak and take on water

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Buying Guide: Selecting the Right Snorkel

So far, you are pretty much an expert on snorkels. You know how they work, the different types, and the features each type has to offer.

But here is the thing, if all snorkels on the market were your typical dry, semi-dry, or wet types, there wouldn’t be these many products on the market! Each company tries to bring new features in order to stay ahead of the competition.

This makes choosing the right snorkel a bit difficult unless you know what to look for. In addition to ease of use, cost, efficiency and safety that we have already talked about above, here are some factors that you should definitely take into consideration.

Purge Valve

One of the first things you need to decide is whether or not you want your snorkel to have a purge valve. As mentioned earlier this feature lets you expel water easily.

If any water should find its way into your snorkel tube, all you have to do is exhale and it will go right back out through the valve. Purge valves make it infinitely easier for divers to clear water.

On the other hand, if you favor a snorkel that doesn’t have a purge valve, you will have to exhale forcefully to clear the water. This takes a bit of practice and can be somewhat difficult for first-timers.

In fact, a lot of first-time divers end up hating the whole snorkeling experience after swallowing or choking on seawater. If you are worried about having to blast the water out of your snorkel, you might want to favor one that has a purge valve.

Fixed vs. Flex Hose

Most modern snorkels have a fixed/rigid or flexible hose or tube right before the section with the mouthpiece.

Flexible snorkels allow the tube to fall away from your mouth when you’re not using it. This kind of snorkel usually involves a straight tube that allows you to talk freely without having a tube in your mouth.

These are ideal for divers who keep switching between their snorkel and their regulator.

On the other hand, fixed hose snorkels tend to have a curved tube and the mouthpiece literally remains “fixed” to your mouth even while talking.

Flex hose usually has a portion that is made from silicon while fixed ones are made from the same material as the rest of the snorkel.

Curved vs. Straight Tube

A few years ago, you would have had to choose between a straight-tube snorkel and a curved one. Nowadays, you will find that most snorkels are curved because this makes them much more stable and less wobbly when being used.

The only problem worth mentioning with curved tube snorkels is that they tend to create more dead space. This can sometimes make it difficult to breathe through them.

That being said, some people still favor the old straight-tube design. That is perfectly okay. There is nothing wrong with it. It is just less ergonomic than the curved tube.


In terms of design, snorkels can be divided into two types: those with a basic “J-tube” design and those without.

The J-tube is simply a traditional or wet snorkel. It doesn’t have that many features and it can take in quite a bit of water once you go under.

Dry and semi-dry snorkels, on the other hand, usually stay away from the J-tube design.

Replaceable vs. Fixed Mouthpiece

When it comes to the mouthpiece, there are two options to choose from: replaceable and fixed. Which one should you choose? Well, it depends. Do you usually bite down hard and gnaw through your mouthpiece?

If yes, then you should definitely get a snorkel with a replaceable mouthpiece. Otherwise, you will have to buy a whole new snorkel every time you wear through your non-replaceable mouthpiece.

When buying mouthpieces, you will find that the best ones are made from silicone. There are all kinds of shapes and sizes to choose from. Make sure you pick one that is comfortable.

Try to avoid plastic mouthpieces because they are not the best in terms of comfort, flexibility, and longevity. Silicone is definitely a better choice.

A Final Word

Snorkeling is only as fun as you make it. Choose the right equipment and you’ll never forget your adventure. Choose the wrong equipment and well, let’s just say you’ll be miserable.

With this guide, you now know everything there is to know about snorkels, how to choose one, and the best models on the market.  So pick a snorkel and hit the waters.

After all, this planet may be called “Earth”, but all its wonders are in the ocean.

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  1. Table column titles are reversed (dry/wet) for content. At least one bullet point for semi-dry is reversed (relative cost).

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