Although this T-shirt provides protection from the sun, phenomena such as reflections (from the water, sand, etc.), heat, time of day, etc., must be taken into account. Wearing this T-shirt does not exempt the wearer from adopting suitable behaviour: wear sunglasses, wear a hat or cap, regularly apply an appropriate sun cream, drink regularly, etc.

https://www.olaian.fr/conseils/la-protection-solaire-en-surf-tp_3890

All of our anti-UV T-shirts are UPF 50+, i.e. they have the maximum level of sun protection. The choice between them will therefore be made based on the length of the sleeves and will depend on what it will be used for.
The constraints are greatest for surfing so we decided to build our range primarily for surfing.
For surfing, the choice will be made according to the duration of your sessions: 1 hour, 2 hours or 3 hours.

1 hour: Occasional activity. You can choose between a loose fit (priority to ease of dressing and comfort when dry) or a fitted cut (priority to comfort when wet). A loop system to connect it to the shorts ensures the stability of the product.
2 hours: Regular activity. Comfort when wet is enhanced by the seamless panels under the arms and the drawstring which further increases stability.
3 hours: Intensive activity. Additional warmth to help you stay in the water for longer.

The fabric of this OLAIAN anti-UV product blocks at least 98% of UVB radiation and 95% of UVA (UPF 50+). This guarantees effective protection from the sun. It can be used both in and out of the water, for water or nautical sports. The density of the textile fibres filters out UV rays, for long-lasting protection, even after washing. Chlorine-resistant.

UPF is a sun protection factor (Ultra Violet Protection Factor) and is standardised worldwide. It defines the protection level of a fabric and more precisely the proportion of UV rays it lets through. To meet the standards, it must block at least 95% of UV rays. UPF 50+ means that the fabric blocks at least 95% of UVA and 98% of UVB rays.

This anti-UV T-shirt reduces friction with the surfboard or bodyboard. The loose fit of the T-shirt makes it easier to put on and is more comfortable when dry. Choose the fitted cut of the 100 or 500 top if you prefer comfort when wet or wear it under a wetsuit. Limitation of irritation has been proven for sessions of 1 hour. If you plan to surf for more than one hour, the 500 UV top will be a more suitable choice thanks to the seamless panels under the arms.

This anti-UV water T-shirt has a loop at the front to attach the cord of your swim shorts to stop the top from riding up while you surf. This solution is recommended for sessions up to one hour. For more than one hour, we recommend that you choose the UV 500 top, which also has a drawstring at the hips to ensure better stability. Unwanted riding up of the top could cause irritation to the lower abdomen.

The minimum water temperature recommended for the use of this anti-UV T-shirt is 22°C. Air temperature may increase or decrease this recommendation. Our thermal models (over 2 hours) are made of either fleece, neoprene or both. The presence of wind can have an impact which can be uncomfortable as soon as the wind exceeds 15 km/h: In this case, choose a model with neoprene.

Our UV tops are designed to meet the needs of the most demanding surfers. Our design choices also make them compatible with other watersports such as swimming, kite surfing, windsurfing, wakeboarding, water skiing, sea wading or SUP (stand-up paddleboarding).

The environmental impact of the product is calculated over its entire life cycle with different indicators. An overall score (ABCDE) is attributed to help you easily identify the products with the best environmental performance by comparing products of the same type with one another (T-shirts, trousers, backpacks, etc.).
Decathlon has voluntarily opted to apply this environmental labelling scheme.
For more information, visit: http://sustainability.decathlon.com/

OLAIAN, DECATHLON'S SURFING BRAND
Based in Hendaye, in South West France, OLAIAN is Decathlon's surfing brand. In our offices at the water's edge, we can design an anti-UV T-shirt and then on the same day test it directly in real usage conditions.