Foil Assist Mast Set

At the core of this mast is a motor pod that is seamlessly integrated into the mast profile, positioned 17 cm below the top plate. This integration not only enhances aesthetics but also contributes to performance. The mast features internally routed cables, ensuring optimal glide and maximum maneuverability. Its rigid, surf-inspired profile provides precise control and instant responsiveness while minimising drag for smoother, more efficient sessions.

Powered by a high-torque motor with a maximum thrust of 33 kg, the Foil Assist Mast AL enables the use of smaller foils and boards, resulting in greater responsiveness, manoeuvrability, and control. Safety and efficiency are further enhanced by a powerful folding gear propeller that opens and rotates only when the motor is engaged and automatically closes when the ring controller button is released, minimizing drag and enhancing safety during use. For additional torque, you can replace the plastic propeller blades with aluminum power propeller blades.

The placement of the receiver in the battery box on the harness ensures optimal signal transmission to and from the remote, providing reliable power throughout your session. This effectively addresses a common pain point associated with foil assist products, making this mast a perfect option for seasoned foilers looking to push their limits.

 Designed for complete modularity, the Foil Assist Mast AL allows for effortless swapping of the motor and connector cable throughout the entire Assist mast range. Its fuselage adapter system is compatible with most major foil brands, including Duotone, F-One, Armstrong, Gong, Axis, Lift, North, Code, Sab, AFS, and KT, granting you the freedom to use your preferred foils while benefiting from the advanced Duotone Foil Assist technology. Furthermore, the mast can be attached to any mid-length prone or wing board featuring standard US foil tracks, enhancing its versatility.

To maximise battery runtime with your Foil Assist, we recommend using a front wing with a surface area of 900 cm2 or larger, along with a board that has a minimum volume of 35 L. 

Whether you're looking to enhance your sessions or push your performance, every detail of the Foil Assist Mast AL has been engineered for a seamless and intuitive assist experience in all conditions.

HARNESS

Unlike conventional systems that mount the batteries on the mast top plate or the board, the Duotone Foil Assist batteries (2 x 1 kg) are placed in a waterproof box attached to a comfortable waist harness. This arrangement ensures that the board-foil setup remains perfectly balanced despite the motor, preserving the pure feel of foiling as much as possible. A backpack with batteries has the disadvantage of placing weight on the shoulders, which can disrupt balance during turns and quick movements.

With the harness, the weight sits on the hips, where it does not affect your balance, and you have full freedom of movement in your upper body. You will hardly notice the weight of the harness (approximately 3.76 kg, including the box and batteries) after just a few minutes. The connection between the batteries and the motor is made via a cable that runs along a shorter leash from the battery box to the top plate of the mast. The board leash is attached below the cable port of the battery box to the harness. The receiver for the remote control is mounted in the lid of the battery box, ensuring a more reliable connection between the remote and the motor, as the Bluetooth signal is not disrupted by water.

The eHarness has been designed with a clear focus on safety and user-friendliness. The magnetic buckle and the Velcro neoprene strap allow for quick and easy removal. With the adjustable buckle, you can customize the harness to fit your individual waist size. If you need to detach the harness underwater, you can easily do so with a quick tug. Additionally, the harness is made from non-water-absorbing materials and features built-in buoyancy, allowing it to float independently and not pull you down in the water. To prevent the battery box from opening under water pressure, it is protected with a neoprene cover that can be opened using a large zipper.

When developing the Foil Assist, our primary goals were to create a system that is light, small, and simple to maintain, while preserving the pure feel of foiling as much as possible. We achieved this by strategically placing the batteries (2 × 1 kg) in a waterproof case on a waist harness, rather than on the board or the top plate of the mast.

To connect the batteries to the motor integrated into the mast, a cable runs alongside a shorter leash from the battery box to the top plate of the mast. The shorter board leash connects just below the cable port of the battery box to the harness.

Riders will quickly get used to the weight of the harness (approximately 3.76 kg, including the box and batteries), while appreciating the feeling of an evenly balanced board with no excess weight beneath their feet. This innovative battery placement improves the motor’s responsiveness and ensures quicker acceleration compared to traditional battery placements underneath the board.

The harness has been designed with safety and simplicity in mind. Its magnetic attachment system allows for quick and easy detachment, making it user-friendly for all riders. For a tailored fit, the adjustable sizing buckle accommodates various body sizes from S-M to L-XXL. To provide added peace of mind while riding, the harness is equipped with a quick-release safety mechanism. Additionally, it is constructed from non-water-absorbing materials and features built-in buoyancy, allowing the harness to float independently and providing an extra layer of safety in the event of a fall. To prevent the battery box from opening during wipeouts, we included a neoprene cover with an easy-to-open zipper on top.

Recommended Board & Foil Setup

Midfish

Skybrid / Skybrid SLS Crush SLS (40 L)

Duotone Adapter Fuselage Fuselage Aero Tail D/LAB Fuselage Aero AL 3BS

Crest D/LAB

Glide 2.0 D/LAB

Glide 2.0 SLS

Free SLS

Back Wing Stabilizer S Back Wing Stabilizer H Back Wing Stabilizer C