By Chadner Navarro | Photographs by Philip Vukelich for WSJ

Since about the mid-1900s, men's swim shorts have typically been cut from lightweight nylon, polyamides and polyesters that dry fast and let you sport about freely, despite some drawbacks. Now a cadre of brands, from preppy J. Press to chi chi St. Tropez label Vilebrequin, is trying natural textiles again, offering trunks in cotton and even wool -- just like 70-plus years ago.

One reason: However sleek a pair of polyester trunks are, they look like they only belong in the deep end. These natural trunks -- most lined; some treated to dry faster -- often resemble regular shorts, making them far more versatile than their synthetic peers. Non-synthetic cloths also earn environmentally friendly marks (though some of these shorts do retain elasticized waistbands and synthetic lining).

How do they hold up in the water? Historically, well enough. Natural trunks have long been worn to the beach, emphasized fashion historian Sonya Abrego, who cited lined cotton cabana sets from the 1950s and '60s as prime examples. But, she added, "I can't see real swimmers -- athletes or people who swim to work out -- moving away from Spandex."

I'm hardly a "real swimmer." I enjoy floating on my back and seeing how long I can hold my breath underwater, but I won't suffer the indignity of timed laps. Could these be the ultimate shorts for guys like me who want to run errands or grab a drink after a leisurely dip -- without looking like they're in boardies? I borrowed six pairs from brands and put them to the test in New York, near where I live, and on a beach vacation to Portugal. The results were...mixed.

For a soak at a spa complex in Tribeca, I pulled on Industry of All Nations' Clean Boardshorts ($115), crafted from organic cotton in a yellow-orange ombre. Though they skew slim, I never felt constricted -- even when doing a couple of unnecessary lunges to test their limits. Unlike the other styles I tried, they lacked lining, so didn't offer as much support. I still found them very easy when bouncing around the pools, but afterward, it felt like I was wearing soggy chinos (even after I wrung them out and put them back on).

The new Merino Swim Shorts ($280) by Sheep Inc., a knitwear brand, were the most swim-coded, with a glossy, water-repellent, eco-friendly coating. Their charming wave pattern evoked a Katsushika Hokusai woodblock print. They felt great while I thrashed around in a hotel pool on Portugal's southern coast. But when wet, they emitted a wet-dog scent -- not an aroma I want to herald my arrival at a poolside lounge. That lasted until they were fully dry the next day.

If trunks never touched water, Ghiaia Cashmere's Mare design ($245) could have been my pick. The soft, pink cotton and wider cut won me over. But as much as I loved them on land, it felt illegal to wear them wet. They turned see-through, giving off "Wet T-shirt contest" vibes. Plus, the tissue-thin fabric constantly bubbled up as I swam.

Prepster staple J. Press debuted lined cotton swim shorts in 2021 and the collection has grown every summer since. I can see why. Its $89 Madras Batik Print trunks resemble a fun pair of regular shorts. (The lining is polyester.) Their airy, untreated cotton dried swiftly one New York afternoon following a romp at Chelsea Piers pool and hot tub. My friend Joe, a real swimmer, expressed concern about the shorts' "drag," saying he would find the looser fit annoying. (He does silly things like dive into the New York Harbor and race around the Statue of Liberty.) I don't care about drag. These performed well enough for me -- and the price was great.

I tried two Vilebrequin designs: a $300 linen one and a $300 merino-wool take. The wool won. I wore the midnight-blue trunks -- lined with polyamide mesh -- sightseeing in the Algarve. None of my friends suspected I had swimmers on until I walked straight into the sea at day's end. If money were no object, I'd abandon my favorite nylon trunks for them. Treated with a natural polymer, these dried the fastest of any I tried, including the linen Vilebrequins. They were good to go about 10 minutes post-swim (the waistband took longer to dry).

Andrew Fionda, fashion design professor at Savannah College of Art and Design, said wearing wool swim trunks outside the water was common in the early 20th century. "Though wool was still uncomfortable when wet, its structured appearance made it suitable for lounging and strolling...in resort settings," he said. After some beach time, I, too, lounged and strolled in the Vilebrequin wool shorts, sauntering from a seafood restaurant to a nearby design atelier. They were supremely comfy -- and didn't smell like wet Rottweiler.

The Wall Street Journal is not compensated by retailers listed in its articles as outlets for products. Listed retailers frequently are not the sole retail outlets.

(END) Dow Jones Newswires

July 17, 2025 17:30 ET (21:30 GMT)

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