What to Wear Under a Wetsuit (2026)
There's no single right answer, but some choices are more comfortable than others. Here are the common options and what to avoid.
Why Wear Anything Underneath?
- Comfort: a thin layer reduces chafing at the neck, armpits and behind the knees.
- Changing in public: on a beach or boat, swimwear makes changing easier.
- Hygiene: a layer underneath is a good idea with rental wetsuits and helps keep your own suit fresher.
- Warmth: a thin thermal or neoprene top adds insulation in colder water.
Common Options
| Option | Pros | Cons |
|---|---|---|
| Swimsuit or bikini | Simple, hygienic | Straps can rub |
| Jammers or swim briefs | Snug, no bunching | None major |
| Rash guard | Reduces chafing, easier on and off | Adds a thin layer |
| Nothing | Simplest, no seams | Not ideal for rentals or changing in public |
| Thermal top | Extra warmth in cold water | Can change fit |
By Sport
| Sport | Common Choice Underneath |
|---|---|
| Surfing and bodyboarding | Swimsuit, boardshorts under a fullsuit only if snug, or nothing |
| Scuba diving | Swimsuit, dive shorts, rash guard or a thin full-body skin |
| Triathlon | A tri suit, which you then race the bike and run in |
| Paddling | Quick-dry swimwear or a thermal base layer |
Cold Water vs Warm Water
In warm water, a swimsuit or nothing is plenty, and many people skip the wetsuit and wear just a rash guard. In cold water, a thin thermal or neoprene base layer adds warmth, but the biggest gains come from a thicker suit, boots, gloves and a hood. Anything you add underneath should be thin and close-fitting so the wetsuit still seals against your body.
What to Avoid
- Cotton: stays wet and heavy, and chafes.
- Bulky layers: they bunch up and break the wetsuit's snug fit.
- Underwear with thick seams: can rub during long sessions.
Rash Guards
A thin rash guard is a popular choice under wetsuits and also works alone in warm water for sun and board-rash protection.
O'Neill Basic Skins Rash Guard
A basic rash guard from O'Neill. Check the listing for sizes and sleeve length.
Check Price on AmazonCare and Storage
- Rinse your wetsuit in fresh water after every use, inside and out.
- Dry it inside out, then right side out, in the shade; sun breaks down neoprene.
- Hang it on a wide, padded hanger or lay it flat; thin hangers stretch the shoulders.
- Store it somewhere cool and dry, away from fumes and heat.
Tips
- Choose a wetsuit that fits snugly but lets you move. See best wetsuits.
- Use a plastic bag over your foot or hand to slide it into the suit easily.
- Rinse your wetsuit in fresh water after each use and dry it out of direct sun.
- For very cold water, add boots, gloves and a hood, or consider a drysuit. See wetsuit vs drysuit.
Frequently Asked Questions
Do you wear anything under a wetsuit?
Many people wear a swimsuit, jammers or a rash guard. Some wear nothing. It's personal preference.
Can I wear a rash guard under a wetsuit?
Yes. A thin rash guard can reduce chafing and make the suit easier to put on.
Should I wear cotton under a wetsuit?
No. Cotton stays wet, gets heavy and can chafe.
What should I wear when renting a wetsuit?
A swimsuit or rash guard is a hygienic choice for rentals.
How do I prevent chafing?
Choose a well-fitting suit, wear a rash guard and consider a skin-safe anti-chafe product on the neck and underarms.