If you’ve ever come home from a day at the pool or beach with a sunburned scalp, you already know the problem: most hats don’t work in the water. They float off, get soaked, or offer no real UV protection at all.
A proper swim hat for sun protection is different. It’s designed to stay on while you’re actually swimming — and to block the sun while it does it. Here’s everything you need to know before you buy one.
Why You Need a Swim Hat (Not Just Any Hat)
Regular hats — baseball caps, sun hats, bucket hats — aren’t made for the water. The moment you submerge, they come off. And even if you’re just floating or standing in shallow water, a soaked cotton hat provides almost no UV protection.
A dedicated swimming hat for sun protection is made from quick-dry, stretch fabric (like nylon/spandex blends) that:
- Stays put even when you’re swimming laps, snorkeling, or playing with kids in the pool
- Dries in minutes so it’s not a soggy mess on your way home
- Maintains UPF 50+ protection when wet — unlike cotton, which loses most SPF protection when soaked
The scalp is one of the most sun-exposed and most overlooked parts of the body. Hair offers some protection, but not much — and if you’re bald, thinning, or swimming with hair tucked away, your scalp is taking a serious hit every time you’re in the water.
What to Look for in a Swimming Hat
UPF 50+ Rating
UPF (Ultraviolet Protection Factor) is the fabric equivalent of SPF. UPF 50+ blocks 98% of UV rays — the highest protection rating available. Look for this on the label, not just a vague “sun protective” claim.
Secure Fit
The biggest complaint about swim hats is that they don’t stay on. Look for a tie-back or chin strap design, or a snug stretch fit that won’t slip. A hat that comes off every five minutes isn’t a sun protection hat — it’s a floating hat.
Quick-Dry Fabric
Nylon/spandex blends dry fast and maintain their shape and UPF rating wet or dry. Avoid cotton — it gets heavy, takes forever to dry, and offers almost no UV protection once wet.
Coverage
Think about where the sun hits you. A basic cap covers the top of your head. Add a visor and you protect your face. Ear flaps protect the ears and sides of the neck — critical for snorkelers and anyone who spends a lot of time face-down in the water.
Types of Swim Hats
Classic Swim Cap Style
A fitted, stretch swim hat that covers the scalp. Stays on well, dries fast. Best for lap swimmers and pool use. Nammu’s Classic Solid Colors are a great example — snug, secure, and available in sizes from toddler to adult XL.
Swim Hat with Visor
Adds a soft brim for extra face and eye shade. Great for outdoor pools, lakes, and beaches where the sun hits at an angle. The Nammu Classic with Visor keeps the secure fit while shading your face.
Ear Flap Swim Hat
The most coverage you can get in a swim hat. Flaps extend down over the ears and neck sides — essential for snorkeling, sailing, and anyone with ear sensitivity. The Nammu EX UV Pro Ear Flap is our most popular style for water sports.
360° Wide-Brim Swim Hat
Maximum all-direction face and neck coverage. The Nammu 360 All-Around Visor shields from every angle — ideal for open water, sailing, and anywhere the sun is relentless.
Who Needs a Swim Hat Most?
Outdoor swimmers and lap swimmers — if you’re in an outdoor pool regularly, sun damage adds up fast. A swim hat is as important as sunscreen.
Snorkelers and divers — face-down in the water means the back of your neck and head are pointed straight at the sun for hours.
Parents of young kids — children’s skin is more vulnerable to UV damage. A kids’ swim hat that actually stays on is one of the simplest sun-safety wins you can give them.
People with alopecia, chemo hair loss, or thinning hair — hair loss leaves the scalp fully exposed. See our full guide on swim caps for alopecia.
Anyone with fair skin or a history of skin cancer — the scalp needs the same attention as your shoulders and nose.
Do Swim Hats Actually Stay On?
The right ones do. Nammu swim hats use an 80% nylon / 20% spandex blend — the same material used in athletic swimwear — so they conform to your head and stay put through swimming, diving, and wave action.
Can I Use Sunscreen Instead?
You can, but sunscreen on a wet scalp washes off quickly and needs constant reapplication. A UPF 50+ swim hat provides continuous, reapplication-free protection for your scalp — and you can still apply sunscreen to your face, neck, and shoulders.
The Bottom Line
Look for secure fit, quick-dry fabric, and the right coverage for your activity — and you’ll never come home with a sunburned scalp again.
Browse Nammu’s full range of UPF 50+ swim hats — classic caps, visors, ear flaps, and wide-brim styles. Ships worldwide from Canada.