Cruising Angles

dw_chart_cruiseDownwind sails are designed and built to perform within certain angles and wind speeds.

 

The chart opposite gives these in polar form.

 

It will be faster for the boat to keep within these parameters by keeping the sail within its angle/speed envelope, but of course a cruising boat is very unlikely to have this range of sails onboard, and perhaps only one of these will be available for use. The choice of which one to buy and use can depend on the boat – a deep, narrow and heavy boat will be better off with a deeper running sail, and a flatter, lighter boat may be better served with a Code 0 type.