Swim trunks for boys

In this category, you'll find our extensive selection of swim trunks for kids – from the very young to boys up to 16 years old. We've gathered a wide range of swim trunks for boys in various designs and fits, so there's something for every taste and activity. Whether you're looking for simple, black swim trunks or models with colors and patterns, you'll find it all here.

If you're searching for something for the little ones, we also have a large selection of baby swim trunks – including soft and functional diaper swim trunks that make the water experience safe and fun.

When it comes to children's swimwear, a pair of well-fitting and durable swim trunks is an essential part of the gear – whether your child is training for swimming several times a week or just loves splashing around in the pool on holiday.

What should you look for in boys' swim trunks?

When choosing swim trunks for your child, there are several things you should keep in mind – especially if they will be used often or for swim training. At Watery.ie, we've tested our swim trunks in collaboration with Irish swimming clubs, so we know exactly what works in practice.

Here are the most important features to look for:

• Good fit: The swim trunks should fit snugly to the body without being tight or slipping down. This applies to both play and competition – no one should worry about keeping their trunks up after a dive from the board.
  
  
• Durability: They should withstand chlorinated water and frequent use. Our swim trunks are made from quality materials that don't become saggy or fade after a few trips to the pool.
  
  
• Freedom of movement: A well-fitting pair of swim trunks should allow the child to move freely – whether swimming laps or playing in the water. They shouldn't slow down or feel heavy when wet.
  
  
• Functionality: For swim training, tight-fitting models are recommended as they minimize water resistance and help the child have the best possible experience in the water.

If you want to ensure that the swim trunks fit as they should and last long, you can see our entire selection of comfortable and functional models here:
→ Find the perfect swim trunks for kids right here on this page above.

The different types of swim trunks available for kids

There are several different types of swim trunks for kids – and which model you should choose depends on your child's age, comfort preferences, and the purpose of use. Below you'll find an overview of the most popular types.

Triangular swim trunks

Triangular swim trunks are shaped according to the body's anatomy and fit snugly and comfortably around the waist and thighs. They are ideal for swim training and competition as they offer maximum freedom of movement and minimal water resistance.

• Fits snugly and securely

• Optimal for fast swimming

• Often used in competitive swimming

→ See all triangular swim trunks

Square swim trunks (trunks)

This type of swim trunks is similar to the triangular ones but has a slightly more covering fit. They are great for kids who don't feel entirely comfortable in the more revealing models but still want high freedom of movement.

• More covering fit

• Almost the same mobility as triangular ones

• Good for both leisure and training

→ See all square swim trunks

Competition swim trunks

Competition swim trunks are designed for serious swimmers and are made from special compression materials. They fit significantly tighter than regular swim trunks to reduce water resistance.

• Tighter fit (often 2–4 UK sizes smaller than usual)

• Made from technical materials

• FINA-approved models for competition

→ See all competition swim trunks for boys

Swim shorts vs. swim trunks

Swim shorts for kids are a popular choice for the beach and holidays, but they are often loose-fitting and create a lot of water resistance when swimming. If the child needs to move quickly in the water, a pair of tight-fitting swim trunks is clearly preferable.

• Swim shorts are comfortable for relaxation and play

• Swim trunks are better for active swimming

• Less fabric = less resistance

→ See our selection of swim shorts for kids

Comparison table: Types of swim trunks for kids

How to choose the right size children's swim trunks

The size of swim trunks matters more than you might think – both in terms of comfort and getting the most out of swim training. At Watery.ie, our customer service has advised thousands of parents in choosing swim trunks, and we know what works in practice. Here are our top recommendations based on experience from both customers and swimming clubs.

• For leisure and play in the water, you should generally choose the size your child normally wears in clothes. The swim trunks should fit without pinching and allow free movement for fun in the pool or on the beach.

• For competitive swimming or intensive training, we recommend going 2–4 UK sizes down. This provides a tight fit that reduces water resistance and improves performance. A good rule of thumb is that the swim trunks should only be able to be pulled 2–3 cm away from the leg.

• If you're unsure between two sizes, this rule of thumb applies: Choose the smaller one for sport and competition, and the larger one for leisure and comfort.

• Remember, the fit can vary slightly between brands. We always recommend checking the specific size guide, which you can find on each product.

→ See our full size guide for each pair of swim trunks on the product page

Swim trunks for kids – choose the right type for sport, play, and water fun

When choosing swim trunks for your child, it's important to consider what they will primarily be used for. There's a big difference in needs, depending on whether it's about fun at the beach, serious swimming, or water sports like SUP and surfing.

For play and relaxation in the pool or on the beach, many choose colorful and patterned swim trunks – often in the form of swim shorts. They are comfortable and airy but not optimal for swimming, as the loose legs and extra fabric create water resistance and hinder movement.

For swim training and competition, tight-fitting swim trunks are recommended. They reduce water resistance, improve swimming performance, and stay much better on the body when jumping, swimming, or training hard. Many swimmers notice a significant difference in both speed and comfort when switching from swim shorts to tight-fitting swim trunks – and there's rarely any going back.

For water sports like surfing or SUP, you should choose a more robust and supportive model that can withstand movement and friction against the board or wetsuit. Here, both fit and durability are important.

And for the very youngest, despite cool designs on swim trunks for kids, it would be a good idea to choose UV swimwear for kids. It will provide much better protection for their delicate skin, which is necessary when children don't have a natural defense against the sun's harmful rays.

So there's a big difference between swim shorts and swim trunks for boys – and it's not just about appearance:

• Swim shorts are perfect for relaxation and holidays

• Swim trunks are clearly best for movement, training, and sports

• Tight-fitting models provide both function and a more targeted, sporty look

• UV swimwear is best for younger children, on the beach or in the pool

How to best care for your swim trunks

A good pair of swim trunks can last a long time – but only if you take good care of them. Many forget that chlorinated water, sun, and moisture can quickly wear out the material. Here are our best tips to make your swim trunks last season after season:

1. Rinse them immediately in cold water

After each swim – especially in the pool – the swim trunks should be thoroughly rinsed in cold water. This removes chlorine and prevents the fabric from expanding or losing elasticity.

2. Hang them to dry immediately

Don't leave the swim trunks wet in the bag. Hang them to dry as quickly as possible, preferably in a place without direct sunlight. This extends both durability and prevents bad odors.

3. Check the swim bag before you leave

It sounds simple, but many forget the swim trunks at the pool. So remember to check if they've come home – otherwise, it doesn't matter how well you take care of them.

Order new swim trunks for kids now, while we still have the model you want!