Most yachts and boats will be built to comply with one of the many sets of regulations that are currently in force. Recreational boats sold in Europe have to meet the regulations that have resulted from the European Directives 94/25/EC and 2003/44/EC for the Construction of Recreational Craft. These are collectively known as the RCD and are supported by numerous exemplifying ISO Standards, the most important of which is probably the ISO12217 Standard relating to Stability and Buoyancy. Although not covered by the RCD, racing yachts on ocean races are normally required by the event organisers to demonstrate sufficient stability characteristics to cope with the course. The yacht’s degree of stability is checked by the application of the STIX stability index system, which provides a numerical value for the yacht, primarily based on the characteristics of the righting lever curve. UK vessels up to 24m in length in commercial use for sport or pleasure, workboats and pilot boats are generally designed, built and equipped to comply with the MCA Code issued as MGN 280 (M), or one of the four codes that preceded it, which are still accepted. Depending on the area of operation, these regulations require the vessel to meet specified criteria for stability and may also stipulate that an approved stability booklet is kept on board. Larger yachts in commercial use need to comply with the MCA Code known as LY3. The Classification Societies, such as Lloyds Register, Bureau Veritas, Det Norske Veritas and others, publish Rules which set a technical standard intended to ensure that craft are built and maintained to a defined level of build quality and structural integrity. A yacht that is built and maintained to the highest standards of Lloyds Rules is assigned the famous Lloyds 100A1 Classification. An experienced Naval Architect such as myself will have worked with all the major Rules, Regulations, Codes and Standards applicable to small craft and be well-placed to advise owners and boat-builders on ensuring their boats are fully compliant and legal. My services include checking for compliance, assessing stability, calculating STIX values, carrying out inclining tests, compiling and checking stability booklets, writing Owners Manuals and Technical Files, and if required, designing aspects of the boat to meet the regulations.