MARITIME – AILING PERFORMANCE CALCULATOR
Sail Area Wetted Surface
A precise tool.
What is the Sail Area Wetted Surface & How does it work?
Sail area represents the total surface of all sails that capture wind energy, typically measured in square metres. Larger sail area can generate more driving force, but also increases heeling and handling demands.
Wetted surface is the total area of the hull and appendages that are in contact with water, influencing viscous drag. A greater wetted surface generally reduces speed, especially in light wind conditions.
The sail‑area‑to‑wetted‑surface ratio (SA/WS) provides a quick indicator of a vessel’s power‑to‑drag balance. Higher ratios suggest a performance‑oriented design, while lower ratios point to a more stable, cruising‑oriented hull.
\frac{A_{sail}}{A_{wet}}
R = Sail Area / Wetted Surface
Parameters
Result
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Frequently Asked Questions
What is sail area in maritime terms?
Sail area is the total surface of all sails designed to capture wind energy, measured in square meters.
How does wetted surface affect a vessel’s speed?
A greater wetted surface increases viscous drag, which can reduce a vessel’s speed, especially in light winds.
Why is the sail-area-to-wetted-surface ratio important?
The SA/WS ratio helps determine how efficiently a vessel converts wind into speed and maneuverability.
How do I calculate sail area for my yacht?
Measure each sail’s dimensions, multiply length by height, then sum all sails’ areas to get the total sail area.
What factors should be considered when calculating wetted surface?
Consider the hull shape, appendages like rudders and propellers, and any protruding structures that touch water.
Can a higher sail area always improve performance?
While more sail area can generate more driving force, it also increases heeling and handling demands, which may not always lead to better performance.
What is the ideal SA/WS ratio for different types of vessels?
The ideal ratio varies by vessel type; generally, higher ratios are beneficial for racing yachts, while cruising yachts may prioritize comfort over speed.
Results are for informational purposes only and do not constitute professional advice.