Full wetsuits

Choose your wetsuit thickness based on water temperature: 2 mm for water above 20 °C, 3/2 mm for 16–20 °C, 4/3 mm for 12–16 °C and 5/4 mm for water below 12 °C. For wind sports (kite, wing foil, windsurf), go for a thicker suit, as windchill makes the water feel 2–3 °C colder.

The first number is the thickness on the torso (where you need the most warmth), the second is the thickness on the arms and legs (where you need more mobility). Thicker neoprene insulates better but restricts movement — so there is no point buying a 5/4 mm suit for summer sup on the Adriatic. When choosing, also consider how sensitive you are to cold and how intensely you move during your sport.

Choose a 3/2 mm fullsuit for water between 16 and 22 °C — it covers your whole body, keeps you warm and is the most versatile choice for spring, summer and early autumn on the Adriatic. A 3/2 mm shorty is a less common combination; shorty models are usually 2 mm, for water above 20 °C.

If you mostly sup or surf in May, June, September or October, a 3/2 mm fullsuit is the right choice. If you're only on the water in July and August in the warm sea, a 2 mm shorty or a combination of a neoprene top and shorts is a better fit.

A long john (sleeveless) is the best choice for sports where you need maximum shoulder and arm mobility — sup, kayaking, rowing and open-water swimming. It keeps your core warm without restricting movement in the shoulders.

The long john is popular with competitive sup paddlers and kayakers because it allows powerful, wide strokes without tight sleeves. For women, the identical cut is called a long jane. In colder conditions, you can wear a neoprene top under the long john or a windbreaker over it.

A neoprene top is enough in water above 22 °C and for short sessions of up to 1 hour — it protects your torso from wind and sun, but isn't made for longer exposure to cold water. A full wetsuit (fullsuit) is needed in water below 20 °C or for longer sessions (more than 2 hours), when your body starts losing heat faster.

Rule of thumb: if you feel cold in your torso, legs or arms after 30 minutes on the water, you need a full wetsuit. A neoprene top is mainly suited to summer sup on the Adriatic and to situations where you only need UV protection and protection from board rash.

A wetsuit should sit close to the body without gaps, wrinkles or stretched areas — especially in the back, under the armpits and behind the knees. It must not restrict your breathing or shoulder movement, but it also must not be loose, as cold water settles into the gaps and destroys the insulating function.

Check that the suit doesn't bunch into folds around the waist and that the sleeves and legs reach your wrists and ankles without rolling up. With O'Neill, we also recommend the intermediate sizes (MT, MS, LS, XLS) for tall, shorter or sturdier builds. If you can't find the right fit among the standard sizes, visit our store in Ljubljana — we will help you try them on.

A front zip offers better sealing and less cold water entry, so we recommend it for more experienced users and colder conditions. A back zip makes it easier to put on and take off, so it is more convenient for beginners, recreational users and children.

Front-zip models also usually allow more shoulder mobility, as there is less material and fewer seams on the back. Back-zip models are usually more affordable. For sup, where long and intensive sessions are not typical, a back zip is usually perfectly adequate. For surfing in cold water, a front zip or zipperless model is the more sensible choice.

O'Neill offers four intermediate sizes for a more precise fit for builds that aren't average: MT (Medium Tall) for tall and slimmer builds, MS (Medium Short) for shorter people with a stronger build, LS (Large Short) for a wider and shorter build, and XLS / XLS-Tall for sturdy or very tall builds.

Intermediate sizes matter because a wetsuit only works if it fits snugly to the body — otherwise cold water flushes in and the insulation is ineffective. O'Neill is one of the few brands to offer this range, which is a key advantage for anyone who can't find the right model among the standard S/M/L/XL.

Cold water gets into a wetsuit for three main reasons: too loose a fit (water flushes in through the openings at the neck, wrists and ankles), poor quality or a worn zip (most often on back-zip models), or the wrong zip type for your conditions (a back zip for cold-water surfing).

Solutions: check the size of your suit (you may need an O'Neill intermediate size), replace a worn-out suit (after 3–5 years of regular use, neoprene starts to stretch and lose its insulating power), or consider switching to a front-zip or zipperless model. For very cold water, we also recommend adding a neoprene hood, as the head loses the most heat.

For sup, we recommend a 3/2 mm long john or a 3/2 mm fullsuit with a back zip — a combination of warmth, flexibility and comfort. A long john is ideal for recreational and competitive paddlers because it allows unrestricted shoulder movement when paddling. A fullsuit is better suited to colder days and longer tours, when you also need protection on your arms.

When paddling, you fall into the water less often than when surfing, so zip sealing is not as critical — back-zip models are perfectly adequate and more affordable. For winter sup on Slovenian lakes (Bled, Bohinj), we recommend a 4/3 mm or 5/4 mm fullsuit with neoprene boots and a cap.

A quality wetsuit lasts 5 to 10 years with proper care. Key rules: rinse it in fresh water after every use, occasionally use wetsuit shampoo (not regular laundry detergent), dry it in the shade on a wide hanger (never in the sun or on a radiator) and store it hanging or laid flat, not folded.

Neoprene's biggest enemies are: direct sunlight (breaks down the neoprene fibres), heat sources (radiators, dryers), chemicals (chlorine, laundry detergents) and prolonged folding (causes permanent creases). With regular care, you preserve the material's elasticity and insulating function even after hundreds of hours on the water.