9506.21 - Sailboards and parts and accessories thereof:

This HTS classification covers sailboards, which are specialized watercraft propelled by a sail and designed for recreational and sporting purposes on water. These boards are distinct from other water sports equipment in that they specifically integrate a sail rig, allowing the user to harness wind power for propulsion and maneuverability.

Within the broader category of "Water skis, surf boards, sailboards and other water-sport equipment; parts and accessories thereof," this heading differentiates sailboards from items like surfboards (which rely solely on wave power) or water skis. The primary distinguishing feature is the sail assembly, which is integral to the function and design of a sailboard.

This category further subdivides into specific classifications for complete sailboards and their respective parts and accessories. This granular breakdown allows for precise tariff application based on whether the imported item is a fully assembled sailboard or components intended for its repair or enhancement, such as sails, masts, booms, fins, or foot straps.