BoatingLAB Tests: UPF Shirts

UPF shirts are tested and rated to determine which one blocks UV light the best.

We tested five cool, comfortable boating shirts to find out just how effective UPF ratings are in predicting ultraviolet light penetration.

UVA, UVB and UPF
UVA and UVB light are two wavelengths of ultraviolet light (long and short, respectively) responsible for sunburn, skin damage and eventually skin cancer. UV protection factor (UPF) is a measure of how much UV light is blocked. Ratings of 15 UPF or higher afford good protection. UPF ratings of 50 may be better, but in truth, the higher the UPF factor, the smaller the added benefit.

For instance, you might think UPF 30 is twice as good as UPF 15, but in truth UPF 30 only blocks up to 1.5 percent more UV light than UPF 15. A UPF 50 only blocks up to 3.1 percent more than 15. The trade-off can be a less comfortable, less breathable garment. Why? Because the tighter the weave, the higher the UPF rating. Darker colors also block more UV light but convert it into heat within the fabric. But that’s where a garment’s design comes in.

To illustrate this we took micro photos of the fabrics to show weaves and then backlit them with UV light to show penetration.

Blocking the Sun
Wearing a tightly woven nylon shirt could feel like wearing plastic wrap if it weren't for wicking fibers, mesh linings and air vents. Tightly woven cotton is a good UV blocker and often feels cooler than synthetics until it gets sweaty. Polyester feels more like cotton but can be woven tighter, dries faster and sports higher "denier" — finer threads and more per inch.

A little-known secret in the UPF wars is that unrated fabrics also deliver strong UV blocking capability, but since they haven’t been proved by tests, these can’t use a UPF rating.

How We Tested
Our test process was simpler than that of ASTM International. However, over time, our tests have shown a strong correlation between the UPF rating and UV light penetration. We used a UV light source and measured the unprotected UV light before each test. Then, we spread the fabric over the light source using a frame for consistent distance from the light. Our measuring device is a General UV513AB UVAB light meter. We calculated UV light blockage with this formula:

1 - [UV light transmitted through the fabric ÷ Total UV light] = UV blockage. Note: UV light was measured in nanometers.

ExOfficio JavaTech Polo
$65, exofficio.com

UPF Rating: 15
% UV Blocked: 94

S Café technology weaves processed coffee grounds into the fibers to increase moisture and odor control. Nope, no coffee smell, and no cooking smells after a toasty afternoon of charcoal grilling. Its UPF offers a great blend of sun blockage and maximum breathability for comfort. Fast-drying and with a breezy form fit.

Material: 53% cotton, 47% recycled poly

Colors Available: Hydrant, Black, Yam, Cobalt, Dusty Olive

Sizes Available: S - XXL

AFTCO Fish Ninja Hoodie
$69.99, aftco.com

UPF Rating: 50
% UV Blocked: 98

Material: 88% poly, 12% spandex

Sizes Available: S - XXXL

Colors Available: Blue, Royal, Silver, Yellow

This poly/spandex hoodie stretches for a form fit. It’s neither too loose nor too tight. With no special fabric treatments but perforated vents in the underarms and sides, it offered a cool, comfortable feel with the bonus of a built-in sun hood and face mask — even the face mask was “perfor-vented” at the mouth and nose for better comfort.

Columbia Airgill Chill Zero
$130, columbia.com

UPF Rating: 50
% UV Blocked: 98

Material: 100% poly

Sizes Available: S - XXL

Colors Available: White, Firefly, Night Tide, Mirage

Tightly woven fabric feels more breathable than nylon, and it boasts Columbia’s sweat-activated Omni-Freeze Zero cooling technology; printed blue dots on the inside react to sweat, enhancing cooling. Also cooling are air vents that face forward, bringing in the boating breeze. Pockets have smooth zippers. The front shirttail features a microfiber sunglass cleaning patch.

Columbia Freeze Degree Crew
$60, columbia.com

UPF Rating: 50
% UV Blocked: 99

Material: 92% poly, 8% elastane

Sizes Available: S - XXL

Colors Available: Splash, Radiation , White, Wham, Cinnabar, Black

A compression-style T-shirt, this one form-fits with underarm and side fabric inserts with added ventilation and wicking. The compression fit was a little more binding under the arms than the Helly long-sleeve T, but the Omni-Freeze Zero technology with interior sweat-reactive cooling dots seemed to work fine in our test.

ExOfficio Dryfly Flex
$90, exofficio.com

UPF Rating: 30
% UV Blocked: 99

Material: 68% nylon, 32% poly

Sizes Available: S - XXL

Colors Available: Blue Jean, Arugula, Walnut

Its seriously good sun protection tested above its UPF grade. Its full mesh-lined back has a ventilated cape to mitigate nylon’s tendancy to block ventilation. We like its true fit, stretchable cut with rollable sleeves, and clean front style with just one hidden zip pocket.

Helly Hansen Odin Polo
$65, hellyhansen.com

UPF Rating: 50
% UV Blocked: 99

Material: 95% polyamide, 5% elastane

Sizes Available: S- XXL

Colors Available: Ebony, Light Gray

This shirt is cool and breathable and felt like Columbia's with Omni-Freeze technology (we keep going back to that feature!). The zip collar looks sharp and the fit is true, with elasticity to add comfort while moving about the boat or fishing. A longer tail would be handy for tail tuckers.

Helly Hansen Odin SS Shirt
$65, hellyhansen.com

UPF Rating: 30
% UV Blocked: 100

Material: 100% poly

Sizes Available: S - XXXXXL

Colors Available: Ebony, Bright Orange, Cobalt Blue, Light Moss

Neither snug nor loose, the SS shirt snaps up the front and has a zippered breast pocket ideal for a phone. This fabric is Bluesign-rated, boasts no harsh textile chemicals to enhance the soft, cool feel, and is crafted to meet strict environmental manufacturing standards. It’s comfortable and quick-drying with a crisp, sporty look. We tested it at 50-plus UPF.

Simms EbbTide Shirt
$59.95, simmsfishing.com

UPF Rating: 50
% UV Blocked: 98

Material: 100% poly

Sizes Available: S - XXl

Colors Available: Stonewash, Light Gray, Dill, Slate Blue, White, Dark Khaki, Maverick Blue

It’s got a tough fabric and Cor3 treatment for UV protection. Its button-down collar and tapered-cuff look is made more casual with flap-covered pockets. Mesh panels at the chest and back yolk assist in wicking. The yolk is vented for cooling airflow. This one tested above its pay grade on its UPF rating.

Woolrich Catalyst Shirt
$65, woolrich.com

UPF Rating: 40
% UV Blocked: 99

Material: 65% poly, 35% nylon

Sizes Available: S - XXL

Colors Available: Kelp, Deep Ruby, Slate, Deep Indigo, Atlantic, Charcoal, Lobster

Button-front shirt features one hook-and-loop flap pocket with one zippered breast pocket, plus a large side-entry, mesh fabric chest pocket ideal for sunglasses or added ventilation if left open. A caped mesh back helps keep the soft stretch fabric cool. The thin, tight weave offers surprising sun protection. It tested above its UPF 40 rating.

Woolrich Tectonic Shirt
$69, woolrich.com

UPF Rating: 20
% UV Blocked: 98

Material: 78% poly, 22% nylon

Sizes Available: S - XXL

Colors Available: Avocado, Ocean, Mushroom

Cool and comfortable fabric is stretchy on the bias for added comfort. It snaps up the front and has a two-snap front bellows pocket with a hidden top entry for sunglasses or phone. The loose fit was cool and comfortable on our humid test day. We were surprised at its low-advertised UPF rating, when our meter showed 98 percent UV blockage.

Woolrich Windwood Shirt
$69, woolrich.com

UPF Rating: 50
% UV Blocked: 99

Material: 100% nylon

Sizes Available: S - XXL

Colors Available: Copen, Olive Drab, Mushroom

Long, rollable button-up sleeves offer ideal versatility. It’s soft and stretchy, and the fit is breezy. Full nylon tends to be less breathable than other fabrics, but it dries quickly. A mesh inner yoke cools the back and shoulders, and the back is vented. Cuffs are tapered to the bottom of the wrist to minimize wear. This shirt crosses easily between business casual and boating fun.

ExOfficio Vent'r Skim'r Pant
$65, exofficio.com

UPF Rating: 30
% UV Blocked: 99

Material: 100% nylon

Colors Available: Dark Charcoal

These comfortable shorts are knee length and lightweight and boast plenty of convenient pockets. They tested above their UPF rating, but we wondered why shorts would be rated at all, since they leave the vulnerable calves unprotected.

Simms Flyte Pant
$79.95, simmsfishing.com

UPF Rating: 50
% UV Blocked: 99

Material: 100% nylon

Sizes Available: S - XXXL

Colors Available: Dark Khaki

Casual cargo pant with Cor3 technology to add UV resistance, breathability and anti-microbial elements to battle odor. Slash pockets with mesh linings on the front and hips give easy access and ventilation. A zip-entry side pocket gives easy access sitting or standing. Cuffs are boot-style with snaps to ease tucking.

Simms Rogue Pant
$99.95, simmsfishing.com

UPF Rating: 50
% UV Blocked: 100

Material: 93% poly, 7% PU

Sizes Available: S - XXL

Colors Available: Black

This pant is most suited to cold weather thanks to its soft, neoprenelike fleece lining swater shedding surface. It provides ideal warmth and sun protection on brisk boating or fishing days. Its cut is dockside casual.