Wetsuit: What Is It And How Does It Work?

by Joost Nusselder | Last Updated:  08.02.2023
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Have you heard of a “diving skin”? Don’t worry, it’s just a wetsuit. Here’s what you need to know:

A wetsuit is usually made of foamed neoprene, worn in water sports like surfing and diving. It provides thermal insulation, abrasion resistance, and buoyancy by using bubbles of gas enclosed within the material, which reduce its ability to conduct heat and provide a low density for buoyancy in water.

You might think a wetsuit would make you too hot, but it actually keeps you cool because it’s thin and tight. It also stops water from passing through, which helps you stay warm in the cold water. HOW? Let’s find out shall we?

What is a wetsuit

What’s the Deal with Wetsuits?

Have you ever wondered what all the fuss is about wetsuits? Well, let us tell you – they’re pretty darn cool! Here’s what you need to know:

What is a Wetsuit?

A wetsuit is a special type of clothing made from multiple layers of synthetic rubber called neoprene. Neoprene is a foam rubber with nitrogen gas bubbles trapped inside, making it an excellent heat insulator. Most wetsuits also have a thin layer of metal like titanium or copper to reflect your body heat back inside.

How Does a Wetsuit Work?

When you step into the ocean, some water seeps in between the neoprene and your skin, and your body quickly warms it up. This creates an insulating layer of rubbery material, warm water, and multiple layers of insulation that work together like your own personal radiator!

Here’s what you’ll find between your body and the cold sea:

  • A thin layer of trapped water warmed by your body
  • A layer of nylon or other comfortable fabric to stop the neoprene from rubbing or chafing
  • A thin layer of heat-reflecting material based on a metal oxide like titanium, copper, silver, magnesium, or aluminum
  • A thick layer of neoprene containing trapped bubbles of nitrogen
  • A durable outer layer made from some water- and abrasion-resistant material

Keep That Water Out!

For a wetsuit to work properly, any water that seeps in needs to stay inside and stay warm. That’s why the seams of a wetsuit are held together with special waterproof tape and blind-stitched (the stitch holes go only part of the way through the neoprene from the inside). Wetsuits also have tight-fitting cuffs and legs to keep cold water out.

So there you have it – now you know the secret behind wetsuits!

The History of the Wetsuit

The Inventor

Surfing and diving have been around for centuries, but it wasn’t until 1951 that the modern-style neoprene wetsuit was invented. This genius invention was brought to us by Hugh Bradner, a physicist from the University of California at Berkeley who was working for the US Navy at the time.

The Inspiration

Hugh Bradner didn’t invent neoprene, which was one of the synthetic fabrics developed by Wallace Carothers, pioneer of nylon. But he did come up with the idea of an insulated suit to keep you warm in the water.

Four years before Bradner’s invention, Harvey L. Williams of Hadlyme, Connecticut filed a patent application for a diving suit with elaborate mechanisms to keep the water out and multiple layers to keep the diver warm.

The earliest example of a waterproof diving suit was Thomas Edgar Aud’s suit from 1927. His suit was made of soft vulcanized rubber or any suitable combination of rubber and fabric and was designed as a suit for life saving, swimming, and analogous purposes.

The Discovery

Where Hugh Bradner really made his mark was in figuring out that the cellular structure of neoprene makes it a superb wetsuit material. He chose not to patent his idea, wrongly believing that only a few hundred people would wear wetsuits. Little did he know that his invention would lead to millions of people taking up cold-water sports such as year-round surfing, swimming, and diving.

The Legacy

Hugh Bradner’s legacy is greater than any financial reward he could have received for his invention. His name will always be remembered as the inventor of the wetsuit, which has allowed so many people to enjoy the wonders of the ocean.

The Different Types of Wetsuits Explained

Winter Wetsuits

When the weather gets cold, it’s time to break out the winter wetsuits. These bad boys are made of 5mm and 3mm neoprene, so you can be sure you’ll stay warm and toasty even when the temperatures drop. They come in full-length “steamers” for maximum coverage, short-sleeved “shorties” for a bit of freedom, and vests and trunks for those who don’t want to be weighed down.

Cold Water Gear

When it comes to cold water activities, you’ll need some extra gear. Neoprene boots and gloves are essential for keeping your extremities warm. For surfing, you’ll want boots with thick polypropylene soles for good grip on your board. For bodyboarding, you’ll want neoprene fin socks with titanium lining for maximum flexibility.

Putting it All On

Putting on all this gear can be a bit of a hassle, but it’s worth it when you’re out in the water. It might look a bit weird, but you’ll be ready for anything the ocean throws your way! Just make sure to take off your fin socks when you’re done, or you’ll find yourself with some pretty worn-out socks.

What’s the Deal with Wetsuits?

What’s the Material?

Ah, wetsuits. The mysterious and magical garment that allows us to stay warm and toasty in the coldest of waters. But what’s the deal with the material? Well, turns out it’s called chloroprene rubber, but us laymen know it as neoprene. It’s a synthetic rubber that’s super thick and water-resistant, plus it’s got some thermal insulation properties. It’s also foamed, which helps it store heat and gives us a little buoyancy when we’re in the water.

What’s the Lamination?

The outside and/or inside of the wetsuit can be laminated with nylon or lycra. This seals the surfaces and gives us better protection from the elements. The downside is that it makes the wetsuit a bit less flexible. But hey, it’s a small price to pay for staying warm and dry!

What’s a Wetsuit?

What is a Wetsuit Used For?

Do you ever find yourself in a situation where you’re surrounded by water and you’re freezing your butt off? If so, a wetsuit is your best friend! Wetsuits are designed to keep you warm and toasty in the water, and they can also provide some protection from the elements. Here’s a list of activities that are perfect for a wetsuit:

  • Underwater diving
  • Sailing
  • Sea rescue operations
  • Surfing
  • River rafting
  • Whitewater kayaking
  • Endurance swimming

What are the Benefits of Wearing a Wetsuit?

Wetsuits are great for keeping you warm and toasty in the water, but they also provide some other benefits. Here’s a list of some of the benefits of wearing a wetsuit:

  • Thermal insulation: Wetsuits are designed to keep you warm in cold water.
  • Buoyancy: Wetsuits provide some buoyancy, which can help you stay afloat in the water.
  • Protection: Wetsuits can protect you from the elements, such as sunburn, abrasion, and wind chill.

Are Wetsuits Allowed in Open Water Swimming Events?

Ah, the age-old question. Some open water swimming events allow wetsuits, while others don’t. It all depends on the event and the water temperature. Generally, if the water is below 78°F (26°C), wetsuits are allowed. If the water is above 84°F (29°C), wetsuits are usually not allowed. If wetsuits are allowed, swimmers usually have to compete in a separate category and may not be eligible for awards. So, if you’re planning on competing in an open water swimming event, make sure you check the rules first!

How Clothes Keep Us Toasty

The Science Behind It

Have you ever wondered why piling on layers of clothes keeps us warm? It’s all thanks to the second law of thermodynamics! Heat flows from hotter objects to colder ones nearby, so when your body temperature is 37°C (98.4°F) and the air around you is 8°C (46°F), heat flows from your body into the air and your body starts to cool.

The rate at which your body loses energy is directly related to the difference between your body temperature and the temperature of your surroundings. That’s why it’s so important to layer up when it’s cold outside.


When you layer up, you’re trapping warm air in between the layers, which makes it harder for the heat to escape. This is called insulation. We insulate the walls and roofs of our homes for the same reason.


Wetsuits are a great way to keep warm when swimming in cold water. The more neoprene, the better! Newer wetsuits are much warmer than older ones, thanks to fewer panels and plastic melted on top of the joins.

Swimming in Cold Water

Swimming in cold water can be dangerous, as it can lead to hypothermia. The ocean water temperature can dip to 6–8°C (43–46°F) in winter, so it’s important to wear a wetsuit if you’re going to brave the cold. The water carries heat away from your body more efficiently than air, so even if the water and air are the same temperature, you can still feel cold.

A wetsuit can extend your swimming season from three months to five, depending on where you live. Check out the chart below to see typical year-round coastal sea temperatures for the South Coast of the UK.

How the Cold Ocean Water Can Make You Feel Like a Popsicle

The Danger of Hypothermia

It’s winter time and you’re standing outside in the cold air, but what if you’re not standing? What if you’re swimming in the freezing cold ocean wearing nothing but a pair of boardshorts? Unless you live in the tropics, the ocean water can get very cold in winter. In a cold, coastal country like the UK, the water temperature can dip to as low as 6-8°C (43-46°F) in February/March. This is when the sea is at risk of hypothermia, a life-threatening condition where your body gets so cold that it can’t warm up again. Swimming in water this cold can be very dangerous and can lead to your heart stopping and death in a matter of minutes.

The Difference Between Air and Water

Water is very different from air, and this can make it even more dangerous. When you swim, there are far more water molecules surrounding your body and they can conduct heat more efficiently than air. This is why you can get in the ocean on a warm summer’s day and still feel freezing, even if the water and air are the same temperature. The water is ferrying heat away from your body like a popsicle.

Charting the Temperature

The chart below shows the typical year-round coastal sea temperatures (in °C) for the South Coast of the UK. It’s clear that the sea temperature is less than half your body temperature (37°C) all year round, and in winter it’s less than a fifth of your body temperature. You can also see that the water temperature lags behind the air temperature by about 2-3 months, making September and October good times to swim even if the air isn’t so warm.

Staying Warm in the Water

If you want to stay warm in the water all year round, you’ll need a wetsuit. A wetsuit can extend your swimming season from three months to five (without gloves and boots) or twelve (with gloves and boots). Even if you miss out the coldest months (December through February), you can still comfortably swim nine months of the year with a wetsuit. Of course, “comfortably” is a subjective word!

Everything You Need to Know About Wetsuit Accessories

The Basics

When it comes to wetsuits, there’s more to it than just the suit itself. To get the most out of your wetsuit, you’ll need to invest in a few accessories. Here’s what you need to know:

  • Neoprene boots, gloves, and hoods are essential for insulation and protection from the elements.
  • Pockets are great for holding small items and equipment.
  • Knee-pads are a must for working divers, as they protect the knees from abrasion and tearing.
  • Some suits come with abrasion protection pads in other areas, depending on the application.

Using Hoods

Hoods are essential for keeping your head warm in cold water. Heat loss from the head can be as much as 20% of the body’s total heat loss, so it’s important to get a hood that fits well and doesn’t feel too tight around the neck. To reduce flushing in the neck area, you can either get a hood that attaches to the top of the suit, or make sure there’s enough overlap between the hood and the suit to constrain the flow.

Wetsuit Boots

Wetsuit boots are a must-have for a variety of water sports, from scuba diving to fishing. They come in different thicknesses, depending on how cold the water is. For warmer climates, a 2-3.5mm bootee is usually enough. The soles are usually reinforced for protection and grip on rough surfaces. For scuba diving, make sure the sole isn’t too thick that it won’t fit over your fins.

Reef Walkers

Reef walkers are small bootees that only go up to the ankle and are usually 2-3.5mm thick. They’re perfect for surfers who want to get out to waves that break at coral reefs or rocky beaches.

Kayaking Boots

For kayaking, short-cut boots are usually used in warmer conditions to give grip and foot protection. In colder conditions, longer wetsuit boots may be used with a drysuit. Split-toe bootees are also available for surfers who want more functionality.

Everything You Need to Know About Scuba Wetsuits

Why Do I Need a Scuba Wetsuit?

Are you ready to take the plunge and explore the depths of the ocean? Well, you’ll need a trusty wetsuit to keep you warm and protected! Wetsuits are like a hug from the ocean, keeping you toasty and safe from the elements and any pesky stinging creatures.

What Do I Wear Under My Scuba Wetsuit?

It all depends on the conditions you’re diving in! You can choose to go with nothing, your swimsuit, a rashguard, leggings, or another wetsuit if you’re diving in colder water. The choice is yours!

Can I Dive Without a Wetsuit?

Sure can! Wearing a wetsuit is recommended for colder temperatures, protection, and to help retain body heat. But if you’re diving in warm water, a swimsuit and a rashguard will do the trick. Plus, the rashguard will give you a bit of a buffer between your skin and the BCD.

Will My Scuba Wetsuit Stretch Out?

Nope! In fact, the material will compress a bit over time. It’s just the nature of the material and wearing it underwater where you’re compressed.

What Does 3/2 mm Mean in Scuba Wetsuits?

It means that the wetsuit has a higher mm on your torso and a lower mm on your arms and legs.

Is a Wetsuit Restrictive?

It can be! The higher the mm, the less range of motion you have. That’s why many people opt for a wetsuit with a higher mm on the torso and lower mm on the arms and legs.


Wetsuit Vs Rashguard

When it comes to swimming in the sun, there’s no better way to keep your kids warm and protected than with a wetsuit. Wetsuits are designed to keep you warm, while rashguards are designed to prevent rashes from surfing. Wetsuits are made of neoprene, a thicker fabric that keeps you warm, while rashguards are usually made of a thinner material. Plus, wetsuits fit snug, so you should buy a size or two smaller than your child’s size to ensure a snug fit. On the other hand, rashguards can make your child colder when it’s windy, so they’re not the best choice for keeping your kids warm. So if you want to keep your kids warm and protected, a wetsuit is the way to go!

Wetsuit Vs Drysuit

Wetsuits are made of rubber neoprene and are designed to keep you warm when wet, but they’re not waterproof. That means if your wetsuit is loose-fitting, you’ll get cold. But if it’s skin-tight, you can move around more easily. On the other hand, drysuits are completely waterproof, but don’t provide much warmth. They fit like a big ski jacket and are great for kayaking, paddleboarding, and taking action photos in the water.

When it comes to cold water activities, wetsuits are the way to go. They fit snugly and allow you to move around more freely. But if you don’t want to get any cold water on your skin and don’t mind the extra bulk, drysuits are a great option. They’ll keep you warm and dry, even in extreme cold conditions. So if you’re looking to stay warm and safe while surfing, wakesurfing, or wakeboarding, make sure you get the right suit for the job.


So there you have it, everything you could POSSIBLY want to know about wetsuits. Now you know why they’re so magical and why they keep us warm and toasty in the coldest of waters.

So get out there and enjoy the water – just don’t forget your wetsuit!

Joost Nusselder, the founder of Kauai Surf Report is a content marketer, dad and loves trying out new sports with everything surfing at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2019 to help loyal readers with surfing and water sporting tips.