← Scroll sideways for more sizes →
X-15
75 · 79 · 85 · 89
BREAK THE SPEED BARRIER
X-15: It’s all about speed. Four all-new 2025 Carbon Reflex Foil Slalom shapes, covering minimum to extreme conditions:
The 2025 X-15 evolution sizes 75, 79, 85 & 89 push the boundaries of aerodynamic improvement. Specifically optimized for use with tiny low drag high speed foils, while enhancing early takeoff practicality. Thinner overall profiles reduce aero drag, and minimize side wind interference. Flatter deck profiles reduce roll, while refined rear strap stance improves high wind control, yet retains light wind efficiency. Maximize your speed potential.
Pure performance. Refined. And Redefined.
THE X-15 IN DETAIL
The Starboard original waterdrop cut-away accelerates the water along the tuck line and gets you to take off speed with minimal delay. With the refined tail profile and enhanced underwater profile, getting smaller highspeed foils started is easier. Get up and fly. 2025 models gain even more stability through optimized aerodynamic airflow, with less aero drag than previous models. Taking it further, we package the whole design in lighter-weight Carbon Reflex technology without compromising strength..
AERO DESIGN
The side profile of the new design is around 10mm thinner, and the rails are much thinner, which reduces aerodynamic drag, and further minimizes the negative effect of side winds interfering with board trim at high speed on the foil. As a result, the 2025 board is even more slippery and stable through the air than the previous benchmarks.
EARLY BOOST
Increasing the bottom wetted surface length by 15cm over previous boosts early subplaning speed and transition onto the foil. This makes takeoffs with smaller highspeed foil wings significantly more efficient, faster and easier.
ADVANCED CUTAWAYS
Extensive cutaways decrease drag before take-off and accelerate the transition into flight mode by quickly reducing wetted surface area as speed increases.
EXTRA CONTROL
A flatter profile under the back foot area reduces rolling action, improves control and highspeed confidence, both at speed and mid gybe.
LOW ROLL CENTRE
Recessed mast track keeps the centre of drive lower and drastically increases your control. Going into gusts or wind holes, sudden power changes or unexpected board movements become easy to control.
EXTRA THIN PADS
There are fewer impacts to absorb when foiling, so we’ve designed the pads to be extra thin for added control and kept the diamond grooves for the perfect grip.
INBOARD STANCE
Bringing the rear strap 3cm inboard delivers more confident control in extreme situations, while at the same time allowing for an outward “on rail” stance alternative for light wind efficiency when required.
JIM DRAKE SLICK FOOTSTRAPS
The Jim Drake Slick foot straps are made with FSC-certified, sustainably sourced and plant-based Yulex foam. With 85% natural rubber content, CO² emitted during manufacturing is reduced by 80%. The remaining 15% of synthetic neoprene is kept to improve UV resistance, carefully sourced with the smoothest fabric for a comfortable feel.
CONSTRUCTIONS
THE FLAGSHIP CONSTRUCTION
The Carbon Reflex construction is our lightest, proven flagship construction and has some of the lowest warranty rates in the industry. Using the lightest biaxial carbon provides more feel, more responsiveness and more controlled flex than conventional boards. On the water, this construction will provide you with ultimate performance. It delivers the most direct feedback from the foil and allows for quicker and more precise movements. With the Carbon Reflex construction you’ll start foiling earlier. For 2025 the Carbon Reflex is limited in stock, built to order with a custom delivery lead time.
X-15 75 Cutting edge. Our narrowest, smallest foil slalom board. Defined for the speed demon who’s looking for sixth gear to reach the outer limits in extreme conditions. As a DefiWind high speed reaching machine, X-15 75 is your weapon of choice. The tail width of 60.3 cm, recommended sail size of 3.5 to 6.0 and even lower aero drag of the 75 ensures your fastest flight session ever in the most stormy or challenging conditions. Confidence at the highest speeds in the most challenging conditions is enhanced by the super secure deep vee frontal profile. Fearless flight.
X-15 79 takes all the development, control and efficiency gains from the new 89 and 85, then turns up the heat... With a narrow 63cm tail and 166 Litres, this is the choice of high windfoil slalom board for those who genuinely seek the outer limits and yearn to burn at the highest possible foiling speeds in extreme conditions. The 79 represents a low-compromise approach to breaking the Vmax barrier, prioritising velocity above versatility. Recommended sail sizes of 5.0 to 7.0. This concept is even more special because it allows you to retain a comfortable, almost parallel stance far outboard, enabling more leverage on the foil.
The X-15 85 is the smaller version of the 89, with more significance in the 7.3cm narrower tail width than the 7 liters actual volume difference. 85 is ideal as a light wind slalom foil board for the lighter sailor. Sails from 6.0 to 8.0 are optimum. A teardrop shape combined with a progressive tail kick helps increase the speed in displacement mode, enhancing speed and pumping ability to get on the foil earlier. The 85 is very stable in the air even when you switch stance, making you less fearful of any touchdown at full speed.
The X-15 89 is the Light wind slalom choice for PWA riders and anyone who wants to go fast in light wind. Recommended sail range is 7.0 to 9.0. Development focused on improved airflow; the new convex front optimises lift versus drag, significantly improving speed downwind, while the clean, faired tail section continues the aero refinement. The recessed mast track improves drive and control, resulting in a more efficient board at low and high speeds, notably quicker acceleration and much calmer at top speed. Thinning the tail allows increased rail pressure, improving handling giving a more natural and connected feel, and a tactical advantage in high-speed racing jibes. For extreme light wind flight.
AVAILABLE SIZES
SPECIFICATIONS
| Model | X-15 75 | X-15 79 | X-15 85 | X-15 89 |
|---|---|---|---|---|
| Volume | 150 L | 161 L | 169 L | 177 L |
| Length | 225 cm | 225 cm | 225 cm | 225 cm |
| Width | 75 cm | 79 cm | 85 cm | 89 cm |
| Tail Width | 60.0 cm | 63.1 cm | 68.2 cm | 76.7 cm |
| Thickness | 14.7 cm | 15.0 cm | 14.4 cm | 14.5 cm |
| Shape | Flat Vee to Double Concave | Flat Vee to Double Concave | Flat Vee to Double Concave | Flat Vee to Double Concave |
| Foil | Without Foil | Without Foil | Without Foil | Without Foil |
| Sail Range | 3.0 - 6.0 m² | 4.0 - 7.0 m² | 5.0 - 8.0 m² | 7.0 - 9.0 m² |
| Weight Carbon Reflex | 8.3 Kg | 8.8 Kg | 9.03 Kg | 9.6 Kg |
Get your dose of windsurfing
directly to your inbox
Subscribe to be the first to know about product releases, receive windsurfing tips or read about exclusive insights right in your inbox.
For every board sold, Starboard plants 3 mangrove trees with Worldview International Foundation. Each Mighty Mangrove sinks down 673kg of VCS certified CO2 during its first 25 years.
Together, our 3 mangroves offset the boards Carbon Emissions 10 X over and fund local livelihoods projects in Myanmar.
Buy a board & we pick up 1.4kg of beach/ ocean plastic trash – equivalent to the amount of plastic trash entering the ocean, per person, per year.