








Electrify your ride
At just 35mm thin, the Foil Drive Assist Slim is specifically engineered for performance-oriented riders looking for assisted power only. Whether you’re carving sharp turns on a prone board, tackling downwind missions in challenging conditions, optimizing smaller gear for wing foiling, or extending your pump foil sessions, the Assist Slim delivers exceptional performance.
While it features a reduced battery capacity that results in shorter runtimes, the Assist Slim still packs a powerful punch for assisted popups. With its low weight strategically positioned under your board, you'll hardly notice it’s mounted - once you’re up on foil, it feels like pure freedom!
Note: The Assist Slim is designed for assisted foiling only and is intended for use to "pop up" on foil then ride unpowered.
Overview
The Foil Drive Assist Slim with NORTH Integration - 80cm Mast
The Sonar AF80 Foil Drive Integrated Masts have a Foil Drive Motor Pre-Installed to the mast at one of three positions.
The Efoil Motor Position offers a complete E-Foil 70cm experience with the motor positioned near the fuselage, while a 20cm and 15cm motor are positioned as a Foil Assist with the motor closer to the board.
The Integrated Mast simplifies installation and significantly improve ride feeling and efficiency. With the motor wiring fully internal, the motor is less noticeable, both when riding powered and non powered, so you can enjoy uninterrupted foiling plus the benefit of electric assistance.
The North Sonar Mast is a refined aluminium foil (AF) section gives the best balance between light weight and increased strength for higher loads. The Sonar Mast features a unique GeoLock tapered geometry locking system. Engineered for strength and stiffness, GeoLock provides a more effective load-bearing connection between the Mast and Fuselage, locking them together, so they feel like one piece. Screws engage the GeoLock, enabling the load transfer to take place over the full cross-section of the mast profile, allowing for a more efficient load distribution and secure connection that is made to last.
Note: The motor is fixed into position on each mast and cannot be removed or changed.
NOT Compatible High Power Motors
Buy Foil Drive Assist SLIM | North Integrated Mast - Wingfoil, Hydrofoils, E-foils @Billy.be: Your Expert in Watersports