Look for lined, quick-dry shorts with a tighter weave.

Buy swim trunks with a built-in mesh liner and a snug fit around the waist and legs. That liner is what stops the ballooning—it holds everything in place so the outer layer doesn’t fill with water like a trash bag.

The drying speed comes from the fabric. Polyester and nylon dry fast. Cotton takes forever and stays heavy. Avoid anything labeled “cotton blend” if you plan to get wet. Also, skip the button-fly cargo style—more fabric, more water, more ballooning.

Pockets matter too. Mesh pockets drain water instantly. Solid fabric pockets hold water and add weight. If the trunks have a zippered back pocket, that’s fine, but the side pockets should be mesh or have drain holes.

For brands, look at ones designed for actual swimming or water sports: Speedo, TYR, or even Patagonia’s baggies if you want the looser look but with a quick-dry lining. Nike and Under Armour make decent options too.

Don’t overthink it. Liner + polyester or nylon + mesh pockets = no ballooning, fast drying.