Cavitation – The formation of vapor bubbles on a foil when water pressure drops too low at high speed or lift. It disrupts water flow, reduces lift, increases drag, and can cause vibration or loss of control.
Foil Arm – The large carbon-fiber arm on each hull that holds and moves the hydrofoil up or down through the foil cant system.
Flight Control System – The onboard network of sensors, hydraulics, and computers that control foil angle, pitch, and ride height for stable foiling.
Gyro Sensor – A high-precision device that tracks the boat’s pitch (up-and-down tilt), roll (side-to-side lean), and yaw (left-to-right rotation), feeding real-time data to the flight controller for stability and responsiveness.
Pitchpole – When the bow digs in and the stern flips over it, causing a forward capsize, often at high speed.
Rake Adjustment – Fine-tuning the foil’s angle to control lift, drag, and boat trim.
Servo Valve – A hydraulic part that makes fast, precise adjustments to systems like foil cant and wing trim.
Yaw Control – Adjusting the boat’s left-right rotation using the rudders and foils.
Flight Envelope – The safe operating range of speeds, foil angles, and pitch that allows stable foiling.
Breach – When a foil or rudder lifts out of the water, suddenly losing lift and possibly causing a crash or stall.
Recovery Mode – The process of regaining stable flight after losing lift or ventilation.
Race Strategy & Tactics 🎮
Acceleration Zone – The area before the start line where boats build speed before the start signal.
Apparent Wind – The wind felt on the boat, combining true wind with the boat’s own motion.
Bear Away – Turning the boat away from the wind, often to start foiling or head downwind.
Delta – The time gap between two boats at a mark or the finish line.
Foil Tack – A tack completed while staying on the foils, maintaining lift and speed.
Flight Time – The percentage of a race the boat spends foiling instead of in the water.
Mode Shift – Changing between sailing modes (like low mode, high mode, or flight) to match wind or tactics.
Overlap – When one boat’s bow is ahead of another’s stern on the same leg, affecting right-of-way rules.
Pre-Start Duel – The tactical battle before the start as boats fight for timing and position.
Windward/Leeward Position – The windward boat is closer to the wind; the leeward boat is downwind and often has right of way.
Dynamic Stability – The balance kept through constant foil, rudder, and wing adjustments to stay smooth and steady at speed.
