Why Hawai'i Locals Don't Wear Underwear Under Boardshorts (And Why You Shouldn't Either)

If you've ever been to Hawai'i and spent time at the beach, you might have noticed that locals don’t wear underwear under their boardshorts. In fact, if we see someone rocking boxers or briefs under their swim trunks, we can’t help but think, “Wow, that must be so uncomfortable.” And honestly, it is. Here’s why Hawai'i locals ditch the extra layer—and why you should, too.

It’s a One-Way Ticket to Chafing and Rashes

Wearing cotton underwear under boardshorts in the ocean is a guaranteed way to get chafed. Cotton absorbs water like a sponge, staying wet for way too long and creating friction against your skin with every movement. This is how you end up with rashes in all the wrong places. Boardshorts, especially high-quality ones, are designed to be worn alone, made of quick-drying, lightweight fabrics that prevent this exact problem. So if you're throwing on underwear underneath, you're just making things worse for yourself.

Boardshort Liners Are Just as Bad

Some brands include mesh liners in their swim trunks, but locals know those are just as uncomfortable as wet cotton. The mesh easily traps sand, leading to irritation and discomfort. It’s also not a great sustainable choice—most boardshort liners are made from synthetic mesh that adds unnecessary extra fabric and doesn’t break down easily in landfills. That’s why many high-end and sustainable swim brands (including ours) have moved away from lining boardshorts altogether. Less fabric means less waste, and a better experience in the water.

Boardshorts Are Already Made of Swim-Friendly Material

If you think about it, boardshorts themselves are made of quick-dry, lightweight nylon or spandex blends—the same materials used in swimwear. In a way, they already function as their own built-in underwear. So why add an extra, soggy layer? If you’re worried about support, there are compression short options specifically designed for water use, but standard underwear just isn’t made for this.

Style Matters: No Puff, No Bulk

Another reason we skip the liner? It messes with the fit. Mesh liners and extra layers of fabric can make boardshorts look puffy, baggy, and bulky—definitely not the sleek, tailored fit you want. If you’ve ever noticed that high-end swim brands tend to avoid liners, it’s because they know this too. Keeping things simple makes for a better-looking (and better-feeling) fit.

The Bottom Line: Just Don’t Do It

At the end of the day, locals in Hawai'i have figured out the best way to wear boardshorts—just as they are. No underwear. No liners. Just comfortable, breathable swimwear designed to move with you. So next time you hit the beach, ditch the extra layer, and experience the ocean the way it’s meant to be enjoyed.

Trust us—you won’t go back. Shop Tai Swim's Collection of liner-free boardshorts now.