The single best thing you can do for men's swimwear is rinse it in cool, clean water as soon as you get out of the pool or sea, then hand wash it gently and dry it flat in the shade. Chlorine, salt, sand, sunscreen and strong sunlight all wear down stretchy swim fabric over time, and a two-minute routine after every swim keeps colours bright and waistbands springy for many more summers.
Why swimwear needs different care from underwear
Swim briefs and trunks are built from stretch synthetics such as polyester, polyamide and spandex or elastane. These fabrics dry quickly and hold their shape in water, but they meet things your everyday underwear never does:
- Chlorine in pools slowly breaks down elastic fibres, which is why old swimwear goes baggy at the seat and waistband.
- Salt water leaves crystals in the fabric as it dries, making it feel stiff and rubbing at the fibres.
- Sand works into seams, linings and drawstring channels and acts like fine sandpaper.
- Sunscreen and tanning oil can leave yellowish marks, especially on white and pastel colours.
- Direct sun and heat fade dyes and dry out elastic when a wet suit is left baking on a lounger.
None of this means you need special products. It just means timing matters: the sooner you remove these residues, the less work they do on the fabric.
The after-swim routine, step by step
- Rinse straight away. Use the poolside or beach shower, or a sink back in your room. Cool water is best. Squeeze it through the fabric a few times rather than just letting it run over the surface.
- Shake out sand. Turn the briefs inside out and flick out sand from the lining, pouch and waistband channel before it dries in.
- Hand wash later the same day. A small drop of mild detergent in a basin of cool water, a gentle swish for a minute or two, then a thorough rinse.
- Press, don't wring. Roll the suit in a towel and press to remove water. Twisting stretches the elastic and drawstring channel.
- Dry flat in the shade. Lay it on a towel or drying rack out of direct sun. Quick-dry fabrics usually need only a short time this way.
If you travel light and have no laundry facilities, our guide to hand washing underwear while travelling covers the sink-and-towel method in more detail; it works just as well for swim briefs.
Chlorine, salt water or both: what changes
| Situation | Main risk to the fabric | What to do |
|---|---|---|
| Indoor or hotel pool | Chlorine loosening elastic | Rinse right after, wash the same day, rotate two suits if you swim daily |
| Sea and beach | Salt stiffness and sand abrasion | Shower rinse, shake out the lining, never let salt dry in overnight |
| Long sunbathing sessions | Fading and sunscreen marks | Let lotion soak in before dressing, rinse oily spots promptly |
| Hot tub or spa | Heat plus chemicals together | Use an older pair, rinse thoroughly afterwards |
A simple habit that pays off: if you swim several days in a row, keep two pairs and alternate them. Elastic recovers best when it has a full day to dry and relax between wears.
Washing machine or hand wash?
Hand washing is the gentlest option and takes only a few minutes. Some swimwear labels do allow machine washing; our Sport Swim Briefs, made from 80% polyamide and 20% elastane, list machine wash in their care instructions. If you use the machine, these settings protect the fabric:
- A cold, delicate cycle with a low spin.
- A mesh laundry bag, so drawstrings and aglets don't tangle with other clothes.
- No fabric softener, which can coat stretch fibres and reduce how quickly they dry.
- No bleach, even on white swimwear.
- Washing with other lightweight items, not with jeans, towels with zips or anything rough.
Whatever the label says, skip the tumble dryer. High heat is the fastest way to tire out elastic and drawstring waistbands. For more general laundry advice, see how to wash men's underwear so it lasts longer.
Keeping prints, metallics and bright colours vivid
Bold swimwear is half the fun of a summer wardrobe, and it rewards a little extra attention:
- Printed styles: wash inside out so the printed face rubs less against other fabric. Our Printed Quick Dry Swim Briefs use 90% polyester and 10% spandex with colourfast prints, and inside-out washing helps keep them that way.
- Metallic finishes: hand wash only, never iron, and dry flat away from direct sun. Avoid scrubbing the shiny surface.
- White and pastel colours: rinse sunscreen marks before they set, and dry in the shade to avoid uneven fading.
- Colour-block styles: wash with similar colours the first few times.
Storing swimwear between holidays
Most swimwear damage at the end of summer happens in the drawer, not in the water. Before you put a pair away for the season:
- Give it one last full wash, even if it looks clean, to remove any hidden chlorine or salt.
- Make sure it is completely dry. A slightly damp suit folded into a bag can develop marks and a musty smell.
- Fold loosely or roll it, and keep it away from heat sources such as radiators.
- Store it in a breathable cotton pouch rather than a sealed plastic bag.
- Loosen the drawstring so the waistband isn't held under tension for months.
When the next trip comes round, try it on before you pack. If the seat sags or the waistband no longer springs back, it is time for a fresh pair. Not sure which cut to replace it with? Our comparison of swim trunks, swim briefs and board shorts can help.
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Frequently asked questions
Do I really need to rinse swimwear after every swim?
Yes. A quick rinse in clean water removes most of the chlorine or salt before it dries into the fibres, and it is the habit that makes the biggest difference to how long a suit lasts.
Can I put swim briefs in the dryer?
It is best not to. Heat weakens elastic and can distort drawstring waistbands. Quick-dry fabrics dry fast enough laid flat in the shade.
How do I get rid of a chlorine smell?
Soak the suit for a few minutes in cool water with a little mild detergent, rinse well and dry it in fresh air. Washing on the same day you swim usually stops the smell from building up.
Why has my swimwear gone baggy?
Repeated exposure to chlorine, heat and wringing slowly wears out stretch fibres. Rotating two pairs, rinsing promptly and drying flat will slow this down.
Find your next pair of swim briefs
Good care keeps your favourite suit going for seasons, and a fresh pair keeps your holiday wardrobe exciting. Browse the full men's swimwear collection, or add some colour with our printed underwear and swimwear and the shiny styles in our rave outfits. Every order ships in discreet packaging.
