What Should You Wear Under a Wetsuit? (Dos and Don’ts)
Wondering what to wear under a wetsuit? Discover the best options for men and women, including rash guards, thermal layers, swimwear, and what to avoid.
Whether you’re buying your first wetsuit or preparing for a cold winter season, one question comes up surprisingly often: What are you supposed to wear under a wetsuit?
Should you go completely nude? Wear boardshorts? Slip into a rash guard, a bikini, or specialized thermal undergarments?
The short answer is that it depends on water temperature, suit fit, and personal comfort. However, choosing the wrong undergarment can lead to painful chafing, bunched fabric, restricted movement, and reduced insulation.
In this guide, we break down the best undergarment options for both men and women, explain what to wear in different water temperatures, and highlight the major mistakes to avoid.
Going Nude vs. Wearing an Underlayer: The Pros & Cons
Before exploring specific clothing options, let’s address the most common approach among experienced surfers: wearing nothing under your suit at all.
Option 1: Going Nude (Commando)
Many seasoned surfers prefer wearing nothing under their wetsuit.
- Pros: Direct contact between the suit’s internal jersey lining and your skin provides maximum freedom of movement, prevents fabric bunching, and allows high-end thermal linings to trap water effectively against your skin.
- Cons: Changing on a busy beach requires careful towel-toggling skills. Additionally, if your suit has raw internal seams or fits loosely, direct skin contact can cause rash around sensitive areas like the inner thighs and groin.
Option 2: Wearing a Form-Fitting Underlayer
Wearing dedicated undergarments or slim swimwear is ideal for surfers who want extra privacy when changing, added thermal insulation in freezing water, or protection against skin chafing.
- Pros: Effortless changing in public parking lots, added rash protection, and extra core warmth when using specialized thermal layers.
- Cons: Bulky or improper clothing will bunch up, trap excess water, and cause severe rubbing.
What Men Should Wear Under a Wetsuit
For male surfers, the key rule is to keep undergarments flat, snug, and seamless:
1. Form-Fitting Compression Shorts or Speedos (Best Overall)
A pair of fitted athletic compression shorts or classic swim briefs (Speedos) is the absolute gold standard for men. Made from fast-drying, smooth synthetic materials (polyester or nylon/spandex blends), they sit completely flat against your skin, prevent groin chafing, and won’t bunch up when pulling your suit on.
2. Specialized Thermal Rash Shorts (Best for Cold Water)
In sub-10°C (50°F) water, a pair of thin thermal shorts crafted from fleece-lined polypropylene or thin 0.5mm neoprene worn under your fullsuit provides a massive boost to core insulation without restricting leg movement.
WHAT TO AVOID: Standard Boardshorts or Loose Boxers
Never wear traditional loose boardshorts or cotton boxer shorts under a wetsuit. The excess fabric, waist drawstrings, metal eyelets, and bulky pockets will bunch up around your thighs and waist, creating agonizing friction and painful pressure marks under your suit.
What Women Should Wear Under a Wetsuit
For female surfers, undergarments should prioritize stay-put coverage, flat seams, and zero metal hardware:
1. Form-Fitting One-Piece Swimsuit (Best Overall)
A athletic, streamlined one-piece swimsuit offers excellent coverage and protection. Because it forms a continuous layer over your torso, it eliminates any risk of tops sliding or shifting when squirming into tight neoprene.
2. Athletic Bikini / Two-Piece (Snug & Hardware-Free)
If you prefer a two-piece, choose a sports-style athletic bikini top paired with seamless, high-waisted bottoms. Ensure the top features wide straps and zero metal clasps, back ties, or underwires.
3. Specialized Thermal Rash Vest / Leggings (Best for Cold Water)
For extra warmth in winter, a snug thermal rash vest or full-length thermal leggings worn under your wetsuit adds a vital insulating barrier against freezing ocean swells.
WHAT TO AVOID: Fashion Bikinis with Ties, Bows, or Metal Hardware
Avoid bikinis featuring halter-neck ties, back clasps, metal rings, or decorative beads. When compressed under tight neoprene, metal clasps cut into your spine, and tie-knots create painful pressure points across your neck and back while paddling.
What to Wear Under a Wetsuit by Temperature
Match your underlayers to your surf conditions for maximum comfort:
| Conditions | Water Temp | Recommended Undergarment (Men) | Recommended Undergarment (Women) |
|---|---|---|---|
| Warm Water / Summer | 18°C+ (64°F+) | Commando or Thin Athletic Briefs | Sleek One-Piece or Sports Bikini |
| Cool / Shoulder Season | 12°C – 17°C (54°F – 63°F) | Compression Shorts or Rash Guard | Athletic Bikini & Form-Fitting Rash Guard |
| Freezing Winter | Under 12°C (Under 54°F) | Fleece-Lined Thermal Shorts & Polypro Top | Full ThermalRash Top & Thermal Leggings |
4 Essential Rules for Wetsuit Underlayers
To ensure complete comfort in the water, follow these four rules:
Rule 1: Say No to Cotton!
Never wear cotton undergarments in the water. Cotton absorbs huge amounts of water, holds it directly against your skin, loses all structural shape, and chills you rapidly. Stick strictly to fast-drying synthetics like polyester, nylon, spandex, or polypropylene.
Rule 2: Keep It Completely Flat & Seamless
Any seam, button, pocket, zipper, or tie knot that feels slightly noticeable on land will feel like a sharp rock pressing into your body after two hours of paddling. Choose seamless or flatlock-stitched designs.
Rule 3: Use a Rash Guard to Stop Wax & Neck Chafing
If you experience neck rash from your chest-zip entry collar, wearing a snug UV/rash guard featuring a low crew neck under your suit creates a frictionless barrier that eliminates skin irritation.
Rule 4: Ensure Your Wetsuit Fits Properly First
If you find yourself needing thick undergarments just to fill out empty gaps in your wetsuit, the underlying problem isn’t your underlayer – it’s an ill-fitting wetsuit.
A properly tailored suit should lay flush against your skin without needing bulky clothes underneath to stop water flushing.
The Power of a Precision Custom Fit
When your wetsuit is custom-tailored to your exact physical proportions, the need for bulky under-layers disappears entirely.
At Born Slippy, our made-to-measure custom wetsuits utilize buttery-soft Japanese Yamamoto limestone neoprene paired with ultra-smooth internal jersey linings. Because our suits are cut precisely to your body, they fit like a natural second skin – providing pure, frictionless warmth whether you choose to wear sleek athletic undergarments or nothing at all.
Eliminate fit problems and enjoy frictionless surfing. Explore custom options at Born Slippy.
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