Sailing performance guide
How to read a sailboat polar diagram
A polar diagram maps expected boat speed by true-wind angle across several wind strengths.
Axes and curves
The angle around the plot represents true-wind angle; distance from the centre represents boat speed. Each curve normally corresponds to one true-wind speed.
Targets, not guarantees
Polar values assume a particular configuration and conditions. Predicted polars are best treated as planning and comparison targets, then calibrated with observations from the actual boat.
Apply it to a real design
Calculate these metrics for a sailboat, then compare the result with catalog models.
Open the calculator