What thickness of wetsuit should I choose for a child: 3/2mm or 4/3mm?

Choosing the right thickness for a wetsuit is one of the most important criteria for keeping a child warm , motivated, and safe in the water.
For a parent, understanding the difference between 3/2mm and 4/3mm helps avoid mistakes in comfort… and money.

At ONE SURFING CO. , we equip young surfers with Yamamoto #40 , the warmest and most flexible neoprene in the world. Here's how to choose the right thickness depending on the season and water temperature.

The difference between 3/2mm and 4/3mm (quick and easy)

A combination:

• 3/2mm → 3mm on the torso, 2mm on the arms & legs

• 4/3mm → 4mm on the torso, 3mm on the arms & legs

💡 The greater the thickness → the higher the heat
But → flexibility decreases slightly (except with Yamamoto neoprene).

When should I choose a 3/2mm wetsuit for a child?

The 3/2mm size is ideal for:
✔️ Water temperatures between 14°C and 20°C
✔️ Spring, summer and early autumn
✔️ Short or moderate sessions, even in winter
✔️ Hossegor conditions from April to October

Advantages of a 3/2mm

• Very flexible → perfect for movement

• Easy to put on: important for children

• Lighter weight → more comfort
  

When should I choose a 4/3mm wetsuit for a child?

The 4/3mm is the perfect choice for:
✔️ water between 10°C and 15°C
✔️ Late autumn, winter, cold spring
✔️ children who are sensitive to the cold
✔️ longer sessions

Advantages of a 4/3mm

• Enhanced heat

• Better insulation in cold water
  

• Ideal for motivated children who surf all year round

And with Yamamoto, the difference is even more pronounced.

The Yamamoto #40 neoprene we use:
✔️ is naturally warmer
✔️ Floats better (reassuring for children)
✔️ Absorbs only 2% of water
✔️ dries faster
✔️ retains its flexibility for longer

👉 In Yamamoto, a 3/2mm heats up like a classic 4/3mm .
👉 A 4/3mm is equivalent to some 5/4mm from other brands .

What thickness is required depending on the water temperature? (SEO table)

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How can you tell if your child is cold?

Signs to watch for

• blue lips

• tremors

• rowing difficulties

• energy drop

• want to stop quickly

If one of these signs appears → it lacks thickness .

Parents' number one mistake: buying too big

Many people think:
👉 “I’ll take a size up, it’ll last longer.”

❌ False.
A wetsuit that is too big lets water in → the child gets cold → he stops surfing.

💡 Hence the appeal of the ONE SURFING CO. subscription.
The size adapts to growth at no extra cost .

Conclusion: What is the best thickness?

Simple answer:

• 3/2mm → for water between 14–20°C

• 4/3mm → for water between 10–15°C

• In Yamamoto → a thickness that heats up like the category above

• For a growing child → opt for a flexible system (subscription)

The main thing is to keep the child warm so that they can progress and have fun.

Give your child the right thickness — and the right size, all year round.

👉 Discover the children's subscription here .
👉 See our 3/2mm and 4/3mm combinations here .
👉 Why choose Yamamoto? Find out more here .

FAQ

1. What thickness of wetsuit is needed for a child?
3/2mm for hot/moderate water, 4/3mm for cold water. Yamamoto pipes offer superior heat resistance.

2. Is a 4/3mm too hot?
Not suitable for children who are sensitive to the cold or for water temperatures below 16°C.

3. Does thickness change mobility?
Slightly, except in Yamamoto where the flexibility is very high.

4. Is a different combination needed in winter and summer?
Yes, unless you have a subscription and can switch between them.