Diving Wetsuit Thickness Guide: How to Choose

Diving wetsuits are essential pieces of equipment for any scuba diver or freediver.

They provide thermal insulation and protection against the elements, as well as adjust buoyancy and offer abrasion resistance.

Read on to discover what wetsuit is best for you, it comes down to water temperature, the type of diving and more.  

When selecting a diving wetsuit, one of the most critical factors is its thickness. The suit’s thickness determines how much insulation it provides and, as a result, how warm you’ll be while submerged. Here are the factors to consider when choosing diving wetsuit thickness:

Water Temperature

The water temperature is the foremost significant element to consider when selecting a diving wetsuit’s thickness. For cooler water, you’ll need a suit that provides substantial insulation to protect you from hypothermia. Conversely, for warmer water, a thinner suit is all you require to provide comfort and protection.


The deeper you venture, the colder the water becomes; thus, the water temperature also plays a crucial role in determining the suit’s thickness needed. As a general guideline, for dives greater than 60 feet (18 meters), you’ll need a thicker suit to maintain warmth.

Duration of Dive

Longer dives necessitate more insulation, particularly in colder waters. Ensure you choose a suit that can adequately support the duration of your dive to protect yourself from the cold.

Body Shape and Build

The suit should fit snugly but not too tightly. Ensure you get an accurate measurement of yourself or participate in a proper fitting to ensure you get a suit that fits perfectly. If it’s too big, insulation is less effective. Conversely, if it’s too tight, it will restrict blood flow.

Aquatic Life

In warmer waters, it is common to wear a shorty wetsuit. These wetsuits have short sleeves and short legs. However, it is essential to consider the kinds of aquatic life in the areas where you dive. Although it may be warm enough not to wear a full-length wetsuit, it may be best to stay covered to prevent stings from Jellyfish and other marine organisms.


Wetsuits vary widely in flexibility and mobility; some are more flexible than others. Ensure that the suit provides proper insulation while also giving you the freedom of movement you need for your dive.

Overall, selecting the right diving wetsuit is essential to ensure your comfort, safety, and enjoyment during your dive. Ensure you consider all these factors and choose a suit that provides adequate insulation for the water’s temperature and the duration and depth of your dive.

Recommended Diving Wetsuit Thickness Based on Water Temperature

When choosing a diving wetsuit, it’s important to consider the water temperature as it affects the insulation level that you need. Wetsuit thickness is measured in millimeters and generally ranges from 1mm to 7mm. Here are the recommended diving wetsuit thicknesses based on water temperature:

Water Temperature Above 26°C (78.8°F)

Thickness: 1mm to 3mm

Diving in warm water requires less insulation, so a wetsuit with a thickness of 1mm to 3mm should be sufficient. These wetsuits are lightweight, flexible, and allow for a full range of motion.

Water Temperature 20-25°C (68-77°F)

Thickness: 3mm to 5mm

For water temperatures ranging from 20-25°C (68-77°F), a thicker wetsuit is necessary to keep you warm. Wetsuits with a thickness of 3mm to 5mm provide more insulation, allowing you to stay comfortable for longer periods.

Water Temperature Below 20°C (68°F)

Thickness: 5mm to 7mm

Diving in colder water requires a wetsuit with a thicker layer of insulation. Wetsuits with a thickness of 5mm to 7mm are recommended for water temperatures below 20°C (68°F). These wetsuits provide excellent insulation and keep you warm even in the coldest conditions.

It’s important to keep in mind that individual comfort levels may vary, so feel free to adjust the thickness accordingly. Also, remember to properly care for your wetsuit to ensure maximum longevity and performance.

What Thickness Wetsuit for UK Diving

For UK diving you will want the thickest wetsuit you can get your hands on – at least opt for a 7mm wetsuit. You may even want to consider semi dry suits or even dry suits when diving in Britain.

When diving in cold water you may lose flexibility and some level of comfort by having to go for many layers and potentially a dry suit. A semi dry wetsuit will likely offer you the best balance.

What Thickness Wetsuit for Australia

Lots of divers ask about the conditions in Sydney and what wetsuit to consider – you can get away with 2mm wetsuit styles in Sydney. Although some recommend 3-4mm, according to research and speaking to friends, there’s really no need to go for over a 2mm suit.

Even though water temperature is at below 20 degrees celsius, anything above 2mm is not required.

What Thickness Scuba Wetsuit for the US

The United States has number of dive sites and each has its own conditions. Here are some of the recommendations for different American destinations.

San Diego

You can dive San Diego waters all year round in 2-4mm wetsuits. During the summer a 1mm-2mm will keep you warm. During winter you will need between a 3-4mm wetsuit.

Southern California

You’ll want a 2-3mm wetsuit if you’re scuba diving in California. Most surfers or surface water sports enthusiasts go for a 3/2 wetsuit, a 3mm for the body and 2mm on the arms and legs.

What About Neoprene Wetsuits?

Neoprene can be warm and comfortable but the downside to neoprene is its unsustainability and damage to the ecosytem.

Some of the advanced neoprene designs such as closed cell neoprene and neoprene alternatives offer technology that become more dense deeper underwater. This then provides less escape for warmth and works to ensure less heat loss.

It’s worth noting that more neoprene isn’t eco-friendly and many are reporting how devastating it could be.

How Does a Wetsuit Keep Us Warm?

Wetsuits work by trapping a layer of water between the material and our skin, offering thermal protection.


The thickness of the wetsuit your choose is down to your personal preference. You will find different thicknesses designed specifically for a particular climate.

Maintain your body heat and choose a wetsuit to prevent you from feeling cold during your underwater adventure with a quality wetsuit.

Written by Katy

Thank you for reading. I started KatyJaneDives.com to share my passion for diving. I am an environmental educator, scientist and now an MSDT diver.

This platform has been made to create, connect and share my knowledge in the world of diving.

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