This book has established itself as the standard work on the subject and is acclaimed as a milestone in sailing literature.
The performance of any sailing craft largely depends on the power of the available sail. But sails forces are determined by a multitude of factors, including wind speed, sail area, sail shape, sail settings, the hull, angle of heel, wind gradient, and steadiness of the wind.
From wind tunnel tests which he has conducted, Tony Marchaj describes how these factors affect sail power and why certain rigs are superior in power and efficiency to others. The tests also indicate where improvements in efficiency may be made.
This major work makes a significant contribution to our understanding of the factors which contribute to an efficient sailing rig, and is a landmark in modern thinking on the subject.