An Overview of Subdivision and Damage Stability Requirements Applicable to Large Motor Yachts

The rules addressing the safety of life at sea influence and haracterize the ship design at an early stage, especially in the case of vessels involved in passengers transportation. In the field of pleasure motor yachts, in particular for those of significant dimensions and intended for the commercial use, the design constraints are prescribed in the “MCA Code of Practice”. The compliance with the MCA code is appropriate up to twelve passengers onboard. Due to the enlarging phenomena of ship size in this portion of market, the designers are now considering to comply directly with the SOLAS requirements for passenger ships, eliminating at the same time the twelve passengers limitation. To this regard, as far as the subdivision and damage stability requirements are concerned, the new harmonized rules based on the probabilistic approach have been recently finalized at IMO and in the following years are going to substitute those based on the deterministic approach, now existing within the present SOLAS. The significant revision of the regulation implies a strong change in the design procedure and in the definition of possible design solutions. In the present paper, a brief description and comparison of the requirements contained in the three relevant rules (MCA, SOLAS “deterministic”, SOLAS “probabilistic”) are given from the subdivision and damage stability criteria point of view, together with an application case, developed for a 73 m motor yacht.