The issue of comfort on board of ships, with particular reference to noise and vibrations, has become in the last years of paramount importance. In this situation, the design procedure needs to be developed bearing in mind both the shipowners specifications, that fix very strict limits with regard to this issue, and the international standards, that define what is the acceptable comfort level on board. These standards, that are continously updated, should be at the same time effective and reasonably applicable to ships and should also be somehow simple and easily checkable in order to give an appropriate guide to the designer.