The influence of Damaged Stability Probabilistic Approach on Overall Megayacht Design

The new Passenger Yacht Code (PYC) was introduced with an aim to become a SOLAS equivalent for yachts. In many matters relating to substantial equivalence the PYC calls for enhancement to damaged stability. Deterministic and probabilistic methodologies both have their own advantages and disadvantages, but for yachts of less than 80m to have the choice is a significant departure from SOLAS. This paper investigates the PYC and its probabilistic approach to damage stability by describing the methodology of calculating the probabilities for flooding and surviving as well as its application on a mega yacht, in order to gain more insight into the ships subdivision by an estimation of attained index A and required index R. In this perspective the authors try to evaluate which kind of consequences such a probabilistic approach can imply in the design of a large yacht when dealing with damage stability calculation. A 90 meter superyacht, at these days under design, has been assumed as a case study.