North Sonar AF Board Adaptor

The North Sonar AF Board Adaptor is a CNC-machined aluminum interface component that connects any board with an industry-standard mounting pattern to the North Sonar foil system. Produced by North Action Sports, it serves as the structural link between the board and an AF foil mast, using a tapered geometry locking connection to join the two parts into a single unified assembly. The design is informed by finite element (FE) analysis, which allows North's engineers to reinforce high-stress areas while paring away material where loads are lower, keeping weight in check without compromising durability.

The adaptor ships with a Sonar Board Adaptor Screw Pack A (M8x40 hardware) so riders have the fasteners they need for a standard install.

• Material: CNC-machined aluminum
• Weight: 1,600 g
• Board mounting pattern: Industry-standard 165 × 90 mm
• Mast compatibility: North Sonar AF foil masts only (not compatible with AK kite masts)
• Included hardware: Sonar Board Adaptor Screw Pack A (M8x40)
• Product code: 85010.210090

The Sonar AF Board Adaptor is aimed at riders who already own — or are building up — a North Sonar AF foil setup and need the dedicated mounting interface for their board. Because it fits the widespread 165 × 90 mm four-bolt pattern, it pairs with a broad range of foil-ready boards across disciplines including wing foiling, kite foiling, surf foiling, and tow foiling.

Riders using North's CF carbon masts do not need this adaptor, as those masts connect to the board differently. The AF Board Adaptor is specifically engineered for the aluminum AF mast line, so it suits riders who prefer the durability and value proposition of aluminum over carbon. It is a functional hardware component rather than a performance-tuning choice, meaning any skill level — from first-time foilers assembling a starter package to experienced riders replacing or adding a second adaptor — will find it relevant.

Within the North Sonar ecosystem, the AF Board Adaptor sits alongside other modular components — masts, fuselages, front wings, and stabilizers — that riders mix and match to build a complete foil assembly. North offers a separate Board Adaptor designed for the AK kite-specific mast line; the two are not interchangeable, so buyers should confirm which mast platform they are running before purchasing.

For riders invested in the Sonar AF platform, this adaptor is effectively a required piece of the puzzle unless they opt for a CF carbon mast, which integrates its own board connection. Comparable aftermarket foil-to-board adaptors exist from brands like Slingshot and Armstrong, but cross-brand compatibility varies and the tapered locking geometry used here is proprietary to North's AF mast interface. Staying within the Sonar system ensures a precise mechanical fit and the direct power transfer the platform is designed around.