November 2010 saw the introduction of the new passenger yacht code (PYC) which aims to provide a SOLAS equivalent code for yachts wishing to carry up to 36 passengers. Prior to this code, yachts wishing to carry more than 12 passengers were subject to full SOLAS and Loadline compliance. This paper investigates some of the differences in philosophy between the two compliance options and the impact they may have on large yacht design. Where in the past international conventions have been considered unreasonable or disproportionately onerous for yachts, the PYC applies substantial equivalence to provide additional flexibility to the Naval Architect and Designers. This paper looks at some of these areas to assess the alternative design considerations that must be made or the benefits that can be achieved when applying the substantial equivalence of the PYC. Some of the topics discussed include lifeboats and lifesaving appliances (LSA), windows, doors, fire protection and interior build and construction materials. In many matters relating to substantial equivalence the PYC calls for enhancement to damaged stability. Since 2009, under SOLAS, all passenger yachts are required to meet probabilistic damaged stability requirements. Under the PYC some categories of yacht are also required to meet an ‘enhanced survivability’ standard based on a 2 compartment deterministic approach. This paper also investigates the additional PYC damaged stability criteria and the impact this can have on the subdivision and arrangement of a large yacht.