Board Shorts vs Swim Shorts | What Actually Fits Your Day

One wrong buy and you’re either wrestling a soggy elastic waist through a wave or wearing a performance garment to lounge poolside. The real distinction isn’t just length — it’s what you actually plan to do in the water. Board shorts and swim shorts serve different purposes, and picking wrong can ruin a surf session or make a lazy beach day unnecessarily uncomfortable.

The Core Difference Between Board Shorts and Swim Shorts

Board shorts are purpose-built for surfing, paddleboarding, wakeboarding, and other high-movement water sports. They typically reach at or just below the knee, use quick-dry polyester or nylon with 4-way stretch, have a fixed waistband with a drawcord, and omit the inner mesh liner to reduce chafing during active motion. Swim shorts — often called swim trunks — are designed for recreational pool, lake, or beach use. They’re shorter (often mid-thigh), have an elastic waistband with a drawstring, and almost always include a built-in mesh liner for support and modesty when wet.

The table below compresses the key differences so you can match the right garment to your actual plan.

Which One Should You Buy?

The answer depends entirely on your primary activity.

Choose board shorts if: you surf, paddleboard, wakeboard, bodysurf, or do any water activity where the garment needs to stay put through fast, repeated motion. Quiksilver’s own guide says board shorts are “designed specifically for surfing so they stay up on the waist and move with the body.” The lack of a liner also means less chafing during long sessions. For women, our tested roundup of women’s surfing board shorts covers the options that actually perform.

Choose swim trunks if: you mainly swim laps, lounge by the pool, wade at the beach, or want something easy to slip on and off. The elastic waist and built-in liner make them comfortable for hours of casual wear. They’re also a better choice for frequent pool use — look for chlorine-resistant fabrics if you swim regularly.

Common Mistakes People Make

The most frequent error is assuming “swim shorts” is a synonym for board shorts. The terms are not interchangeable, and buying the wrong one creates real friction.

• Wearing swim trunks for surfing: The elastic waist and liner can shift during a duck dive, and the looser fit creates drag. Worse, the mesh liner can chafe on a long session.
• Wearing board shorts for lounging: You’ll get the secure waist and long inseam, but you’ll miss the comfort of an elastic band and the convenience of a liner for walking around wet.
• Ignoring sun and chlorine protection: One guide explicitly recommends UPF 50+ for extended outdoor exposure, and chlorine resistance matters if the pool is your main venue — not all board shorts or swim trunks are built for repeated chlorinated water.

FAQs

Can you wear board shorts for swimming?

Yes, you can wear board shorts for general swimming, though they are designed for active sports rather than casual pool use. The longer cut and liner-free design may feel less convenient for lounging or quick changes, but they perform fine in the water.

Are swim trunks good for surfing?

Swim trunks are generally not recommended for surfing because their elastic waistband and inner liner can shift during active movement, increasing chafing and creating drag. For occasional or beginner surf sessions they may work, but dedicated board shorts will stay more secure.

What’s the difference in length between board shorts and swim trunks?

Board shorts typically have an outseam of 18 to 22 inches, reaching at or below the knee. Swim trunks are shorter, with an outseam of 7 to 14 inches, often falling above the knee or mid-thigh, though exact lengths vary by brand and style.