Do wetsuits keep you dry?

Jörg Matzdorff
Jörg Matzdorff

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A wetsuit is a tight-fitting garment that provides thermal protection when in the water. It is made of stretchy synthetic rubber material such as neoprene. It is lightweight, flexible and keeps the body warm in cold water.

Dry suits and wetsuits are used for water sports such as diving, surfing, swimming, windsurfing, scuba diving, jet skiing, rafting and so on. Some prefer dry suits to keep warm in cold water, while others prefer the latter. If you are buying a wetsuit for the first time, you may be confused about whether wetsuits keep you dry or not.

That’s why we provide you a very clear overview in this article about:

  • How it comes that wetsuits stay wet in the water but can keep you warm anyway
  • How drysuits differ in their temperature capacity
  • What suit to choose for your activity

Are wetsuits waterproof?

Although wetsuits are made of waterproof materials, they do not keep you completely dry. Wetsuits have a water-repellent inner layer that prevents water from entering your body. However, wetsuits do not keep you dry when you are completely submerged in water because water enters the wetsuit through the neck, zipper, wrists, and ankles.

Your body heats up this thin layer of water quickly. The wetsuit is tight-fitting and prevents water from entering, so your body stays warm and is exposed to only a limited amount of cold water at a time. Wear drysuits if you want to stay 100% dry when diving or surfing in cold water.

Do wetsuits keep you warm in cold waters?

Let’s take a look at the different warmth aspects of a wetsuit when you are cold water swimming.

  • Water conducts heat faster than air due to higher density.
  • You will feel cold for a few minutes when water enters your body.
  • Your body heat warms the thin layer of cold water seeped through the suit and constantly regulates body temperature. 
  • Since the suit is already filled, additional water will not enter inside it when you maneuver in the water.

Thus, a wetsuit keeps you warm in cold water.

Do you wear something underneath a wetsuit?

Most surfers and divers prefer to wear something under a wetsuit. Fitted cycling shorts provide excellent protection for your body and serve as an extra layer when diving or surfing in cooler temperatures. The wetsuit will keep you warmer and give you more buoyancy, as there is a thin layer of water between your body and the neoprene.

 However, keep in mind that anything you wear under a wetsuit, such as gloves, boots, hoods, jackets and vests, will get completely wet. Also, it is advisable not to wear heavy clothing under the wetsuit, as this will be uncomfortable and may make you feel even colder.

What is a drysuit?

A drysuit is a loose-fitting, waterproof suit that is not designed to provide warmth or fully protect the diver. It consists of layers of insulating synthetic materials that prevent the diver from coming into contact with the water. Those who go swimming or diving in the cold wear a drysuit instead of a wetsuit. 

Drysuits are like big bags with holes on the head, legs and sleeves. The seal at the ends of the legs, sleeves and around the neck prevents water from entering the suit.

Features and purpose

Drysuits are characterized by two main features that allow you to extend the time you can spend underwater. 

1. Waterproof

Unlike wetsuits, drysuits are completely waterproof. Your body will never touch the water and  keep you 100% dry and comfortably warm.

2. Loose

They are baggy and fit loosely like a large ski jacket. This is because they maintain a layer of insulating air between your body and the suit, which you can manage via inflation valves that allow you to add gas as you descend deeper. The inflation valve on a drysuit performs a similar purpose to the power inflator on a buoyancy vest and is situated in the middle of the suit’s chest. Drysuits also employ exhaust valves to release air as you climb.

Since drysuits are heavy, they are not suitable for swimming as they restrict the flexibility of movements of hands and legs.

Drysuit vs Wetsuit

You might be wondering the exact difference between a wetsuit and a drysuit. So, here is a small guide explaining the distinction between both. After learning about features and functionalities, you can decide which is best for you.

MobilityEasier to move comfortably and quickly in the waterThey are baggy and slow down the speed of the diver
MaterialFoam neopreneRubber, nylon, or neoprene
Thermal insulationFor cold water. Wetsuits use a layer of water to keep the body insulated. The neoprene contained in wetsuits traps the heat and keeps your body warm.For extremely cold water.Drysuits use a layer of air to keep the body insulated. They are completely sealed to prevent water from entering the body and coming into contact with the skin.Due to their loose fit, you can wear undergarments underneath to enhance thermal protection.
Useful lifeThey are more likely to deteriorate after a few years of regular use.They can last over ten years with proper care and maintenance.
BuoyancyThe wetsuit compresses and becomes thinner as you go deeper into the water. It loses insulation capacity and inherent buoyancy.Drysuits use compressed air to compensate for the increased pressure at the depth. It does not lose insulation capacity.
VersatilityThe wetsuit is not flexible as it cannot adjust to varying water temperatures.A dry suit is suitable for various water conditions- both warm and cold water. You can use it all year round from summer to winter. They are suitable for a wide range of environments.

How does water enter your wetsuit?

Wetsuits are not meant to keep you dry. Despite being composed of waterproof neoprene foam, they allow a tiny layer of water to enter via the zippers, wrists, neck, legs, and ankles. The water quickly condenses into a thin layer of liquid and gets trapped between your skin and the neoprene. Your body heats up this water layer very rapidly. 

Rubber neoprene with small air bubbles traps the heat within the wetsuit. Due to these inherent insulating characteristics, the water can stay warm for a longer time. Due to the tight fit and the water being trapped inside, the neoprene prevents fresh water from entering your wetsuit and this is why you feel warm in the cold water. 

The black color of the wetsuit absorbs heat from the sun as well and shields your skin from harmful UV rays.

Why are wetsuits not waterproof?

All a wetsuit does to keep us warm is employ the insulating properties of both the water and its neoprene material. People also underrate the human body’s capacity for heat production. We generate a lot of heat, and since it cannot leave while we are wearing the wetsuit, we remain comfortably warm. Wetsuits contain multiple layers of cloth to regulate the entire body temperature of the wearer.

The wetsuit traps a thin layer of water between the wearer’s skin and the inner nylon material rather than deflecting water away from them. The insulation to maintain the temperature of the trapped layer of water is provided by the outer layers of the wetsuit, which are created from various materials, including metal oxide and neoprene.

The number of layers in a wetsuit and their thickness differ significantly depending on how much protection you require. A light, short wetsuit would be sufficient for swimming or surfing in temperatures between 18 and 20 degrees Celsius. However, if you are planning to dive or surf in extremely low temperatures, you would need a suit at least 5 mm thick to stay comfortable.

Wetsuits are made with various seams; for example, a glue blind stitch suit is as near to being waterproof as you can get.

How can wetsuits protect you from cold water temperatures?

Wetsuits are preferable when diving in relatively warm water. However, drysuits are recommended for freezy water as they keep you warmer than wetsuits. 

How warm you feel in a wetsuit also depends on the thickness of the wetsuit. This is because insulation depends on the thickness of the neoprene and how much cold water the user can tolerate. In a thicker wetsuit, more heat builds up in the neoprene.

Use the table below to determine the thickness and ideal type of wetsuit depending on the water temperature.

Water temperature(Fahrenheit)Wetsuit ThicknessRecommended wetsuit type (and accessories)Seal type
Below 426/5 mmFull suit + Boots + Gloves + HoodSealed and taped
43 to 525/4 mm Full suit + Boots + Gloves + HoodSealed and taped
52 to 584/3 mmFull suit + Boots + Gloves + HoodSealed and taped
58 to 633/2 mmFull suit + Boots + Gloves + HoodSealed
62 to 680.5 mm to 2 mmSpringsuit/ FullsuitFlatlock
65 to 75Top / ShortyFlatlock
Above 75Rashguard for skin and sun protectionFlatlock

Conclusion: Wetsuits keep you dry if you choose them well

It’s crucial to note that a well-fitted wetsuit can only shield your body from the impacts of cold water. The wetsuit’s insulating qualities will be negatively impacted if there is extra material in some areas, or if the cuffs are too loose. So to answer the question, do wetsuits keep you dry? We can say that they do, if you choose them well.

Always take accurate measurements before buying a wetsuit, and refer to size charts available for men’s, women’s, and children’s wetsuits. 

Jörg Matzdorff
Jörg Matzdorff

Outdoor and surfing enthusiast.

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