Boardshorts vs Trunks vs Bikini Bottoms: Swim Bottoms Compared
By Volcom® | Skate, Surf & Swimwear, Snowboarding Clothes ... | Published: 2026-10-16
Category: Comparisons
Boardshorts, trunks, and bikini bottoms solve different problems. Here's how to pick based on activity, coverage, and fit—plus what to check before you buy.
Quick answer
Choose boardshorts for surfing and high-movement water sports because they stay put and resist riding up. Choose trunks for casual swimming and lounging when you want a shorter, lighter feel. Choose bikini bottoms when you want minimal tan lines and maximum freedom, and accept that they offer the least security in heavy surf.
What actually separates these three
The difference isn't just length—it's how each bottom handles water, movement, and coverage. Boardshorts are built for staying in place: a fixed waistband, a secure closure, and fabric that doesn't stretch out when wet. Trunks sit in the middle: shorter, often simpler, and less technical, which makes them comfortable for swimming but less locked-in during wipeouts.
Bikini bottoms prioritize freedom of movement and minimal coverage. That's a feature, not a flaw—until you're paddling out through whitewater and need the bottom to stay exactly where you put it. The right choice depends on how much time you spend in the water versus on the sand.
Fit and length: what to check before buying
For boardshorts, length is usually measured by outseam. A shorter outseam (around 16–18 inches) sits above the knee and moves easily; a longer outseam (20–22 inches) offers more coverage but can drag when wet. Check whether the waistband is fixed or adjustable—fixed waistbands with a drawstring or lace-up closure stay more secure in surf.
Trunks often have a simpler elastic or fixed waist and a shorter leg. If you're between sizes, size up for swimming comfort, but know that a looser waist can shift in waves. Bikini bottoms are sized like underwear, and coverage varies by cut. A high-leg, skimpy cut like the Coco Low Tide 90s V Bottom sits higher on the hip and offers less rear coverage than a standard or full-coverage brief.
How to match the bottom to your day
If your day includes paddling, duck diving, or any chance of getting worked by a wave, boardshorts are the safest bet. If you're swimming laps in a pool or floating a river, trunks give you room to move without excess fabric. If you're mostly lounging, walking the beach, or taking photos, bikini bottoms keep tan lines minimal and dry fast.
You can also mix categories. A skirted bottom like the Psychonic Skirt adds coverage over a bikini bottom without the bulk of boardshorts—useful when you want to move between the sand and a beach café without changing. And for quick transitions, slides or flip flops are the footwear counterpart to any of these bottoms.
Trade-offs at a glance
- Boardshorts: Best security in surf and high-movement water sports, but more fabric means slower drying and less tan-line coverage. Choose these if staying put matters more than minimal coverage.
- Trunks: Lighter and less technical than boardshorts, comfortable for casual swimming, but a looser waist can shift in waves. Choose these for pool days, lake swims, and lounging.
- Bikini bottoms: Maximum freedom and minimal tan lines, but the least secure option in heavy surf and the most dependent on a precise fit. Choose these for beach lounging, light surf, or layering under a skirt.
Product facts that affect your choice
- Women's Coco Low Tide 90S V Bottom Skimpy: Designed for Volcom's own Coco Ho, the Coco Low Tide 90s V Bottom brings a bold V-front and high-leg cut with skimpy coverage. This cut sits higher on the hip and offers less rear coverage than a standard brief, so it's best for lounging or light surf where you want minimal tan lines—not for heavy wipeouts.
- Women's Psychonic Skirt: The Psychonic Skirt flows in matte satin with an allover print and a bias cut that skims and moves when you do, with a clean waist and side zip. A skirted bottom adds coverage and a dressed-up look without the bulk of boardshorts, making it a practical choice for beach days that move between sand and town.
- Women's Simple Braided Slides: The Women's Simple Braided Slides offer a clean, easygoing look for warm-weather days with a braided texture on a classic flip-flop silhouette. These slides are the easy on-off footwear partner for any swim bottom—useful when you're changing out of wet gear or walking to and from the water.
- Men's Circle Web Belt: The Circle Web Belt keeps it tight with a metal clamp buckle, 1.5-inch polyester webbing, and a cut-to-size fit, plus a hidden bottle opener. If you wear boardshorts or trunks with belt loops, a webbing belt like this adds security and a casual look—and the hidden opener is a small campsite bonus.
Which one should you get?
Best for
- Surfers and anyone doing high-movement water sports (boardshorts)
- Casual swimmers and loungers who want a lighter feel (trunks)
- Beachgoers who prioritize minimal tan lines and freedom (bikini bottoms)
Not for
- Heavy surf if you want maximum security (choose boardshorts instead of bikini bottoms)
- Minimal tan lines if you're mostly sunbathing (choose bikini bottoms instead of boardshorts)
- Technical water sports if you need locked-in fit (choose boardshorts instead of trunks)
