STABILITY OF SAILING CRAFT

This paper presents the results of an investigation of the minimum stability requirements for ballasted, mono-hull sailing craft. Recent sailing yacht casualties are addressed in an attempt to determine potential dangerous stability characteristics in mono-hull sailing craft. To support the development of stability criteria based on this analysis, the stability data of so-called category I yachts (considered suitable for sailing anywhere in the world), of which more than 5 vessels were built and/or with a long operational history without any stability oriented problems, are also considered. A proposal is then made for the minimum value of the vanishing angle of positive stability and the righting moment at 90 degrees of heel, for the four stability categories considered. The development of a so-called dynamic stability factor is also presented. This takes into consideration various factors of importance in a dynamic sense, such as the roll moment of inertia, the loss in waterplane inertia due to the wave through amidships, etc.