At first glance, board shorts and swim trunks can seem like two names for the same thing. Both are made for the water, both dry faster than regular shorts, and today, both come in more lengths and styles than ever.
But the difference becomes noticeable once you start wearing them. The waistband that feels secure while surfing may feel less comfortable during a laid-back pool day. The longer cut that offers protection on a board may feel like unnecessary fabric when you are simply swimming, walking the beach, or grabbing lunch.
In simple terms, board shorts are built primarily for surfing and active water sports, while swim trunks are designed for casual swimming, beach vacations, pool days, and everything that happens in between.
Length is only part of the story. The right choice also depends on the waistband, liner, fit, pockets, and—most importantly—how you plan to spend your day.
What Are Board Shorts?
Board shorts were originally developed with surfing in mind. Their longer cut provides more coverage when sitting or lying on a surfboard and helps reduce direct friction between the board and the skin.
Instead of a fully elastic waist, traditional board shorts use a fixed waistband with a drawstring or lace-up closure. This keeps them more secure when moving through waves. They also tend to have a streamlined fit and fewer pockets, helping reduce unnecessary bulk in the water.
Traditional board shorts are usually unlined, although some modern versions now include stretch fabrics or built-in support. They remain a practical choice for surfing, paddleboarding, wakeboarding, and other activities where security and coverage matter.
What Should You Wear Under Board Shorts?
Traditional board shorts can be worn on their own. However, some men prefer swim briefs or compression shorts underneath for additional support and protection from chafing during longer sessions.
Avoid ordinary cotton underwear. Cotton absorbs water, dries slowly, and may become uncomfortable once wet.
What Are Swim Trunks?
Swim trunks are designed for recreational swimming and everyday life around the water. They are typically shorter than board shorts and use an elastic or partially elastic waistband, often combined with a drawstring for a more adjustable fit.
They also offer more variety in length. Shorter inseams create an athletic, leg-forward look, while 5.5-inch and 7-inch options provide progressively more coverage. Many swim trunks include a traditional mesh liner or a softer compression liner for built-in support.
Pockets are also more common, which makes swim trunks convenient when your day includes more than swimming. A well-designed pair can take you from the hotel breakfast to the beach, into the water, and then to a casual lunch without requiring an outfit change.
Modern men’s swim trunks often add quick-drying fabric and four-way stretch, making them comfortable for walking, playing beach games, or simply spending an entire day outdoors.
The 5 Main Differences Between Board Shorts and Swim Trunks
1. Purpose
The clearest difference is what each style was designed to do.
Board shorts are performance-oriented and traditionally associated with surfing and board sports. Swim trunks are built for more general use, including swimming, vacations, pool parties, and relaxed beach days.
If you are paddling into waves, the security of board shorts can be valuable. If you are swimming, walking, eating, and relaxing throughout the same day, swim trunks are usually more versatile.
2. Length and Fit
Board shorts generally have a longer inseam and may reach close to the knee. Their fit is often streamlined to reduce movement and excess fabric during water sports.
Swim trunks come in a wider range of lengths and usually feel more relaxed. A shorter inseam allows greater freedom of movement and creates a casual vacation look, while longer trunks offer extra coverage without necessarily feeling like technical surfwear.
Not every board short is long and not every swim trunk is short, so length alone should not determine your choice.
If you are unsure how much coverage you need, our guide to choosing the right swim trunks inseam explains how shorter and longer lengths affect both comfort and appearance.
3. Waistband
Most traditional board shorts have a fixed waistband secured with a lace-up front. The stable construction helps keep the shorts in place when diving under waves or getting on and off a board.
Swim trunks generally use an elastic waistband with a drawstring. This design is easier to put on, adapts more comfortably to movement, and tends to feel better during long, relaxed days.
Some newer styles use hybrid waistbands to combine a cleaner appearance with added flexibility.
4. Liner and Support
Traditional board shorts usually do not have an internal liner. Surfers who want additional support may wear compression shorts or swim briefs underneath.
Swim trunks commonly include either a mesh liner or a compression liner. Mesh is lightweight and familiar, while a soft compression liner swim trunks offers closer support and can help reduce skin-on-skin friction. The latter is especially useful for active beach days or extended wear.
5. Pockets and Versatility
Board shorts usually keep pockets to a minimum. When included, the pocket often has a zipper, flap, or secure closure to prevent items from falling out during activity.
Swim trunks are more likely to include side and back pockets, giving them greater everyday versatility. You still should not swim with a phone or wallet in your pocket, but the storage becomes useful when walking to the beach, ordering lunch, or exploring a resort.
How to Choose Board Shorts or Swim Trunks?
Choose board shorts if you:
- Regularly surf or participate in active board sports.
- Need a secure waistband that stays in place in stronger waves.
- Prefer longer coverage and a streamlined fit.
- Do not need a built-in liner or prefer choosing your own base layer.
Choose swim trunks if you:
- Spend more time swimming, vacationing, or relaxing by the pool.
- Want built-in support from a mesh or compression liner.
- Prefer the comfort and adjustability of an elastic waistband.
- Need one pair for swimming, walking, lunch, and casual activities.
- Want more choices in inseam length, color, print, and pocket design.
Neither category is automatically better. The right choice depends on how your day will unfold, not simply what the label says.
Can You Swim in Board Shorts?
Yes. Board shorts are water-ready and work well for surfing, recreational swimming, and active water sports.
However, their longer cut may create more drag than shorter swim trunks, and the lack of a built-in liner may be less convenient for casual swimmers. If you plan to move repeatedly between the pool, beach, boardwalk, and town, swim trunks will generally feel more comfortable and practical.
For competitive or lap swimming, neither loose board shorts nor recreational swim trunks are ideal. More fitted performance swimwear is designed specifically to reduce drag.
Conclusion
Board shorts are the stronger choice for surfing and performance-focused water activities. Their longer cut and fixed waistband provide the coverage and security needed for movement in the waves.
Swim trunks offer greater comfort and versatility for most vacations, pool days, and casual swimming. If your ideal beach day includes getting in the water, walking along the shore, grabbing lunch, and relaxing in the sun, quick-drying swim trunks with a supportive liner will usually be the easier choice.
Explore Maamgic men’s swim trunks in different lengths, prints, and liner styles to find a pair that fits the way you spend your time by the water.
