Approximate leeway angle from the beam-wind component and ship speed, using the rule of thumb: leeway (°) = wind speed / ship speed × f.
Formula
$$ \text{Leeway}^\circ \approx f \cdot \frac{V_\text{wind} \cdot |\sin\theta|}{V_\text{ship}} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $V_\text{wind}$ | True wind speed | kn | anemometer |
| $θ$ | Wind angle off bow | ° | bridge observation |
| $V_\text{ship}$ | Speed through water | kn | log |
| $f$ | Empirical hull factor | - | ship-specific |
Sources
- Bowditch - American Practical Navigator.