The evaluation of the safety state of the ship in a generic operative or emergency condition is a very complex issue due to the huge number of attributes involved in the problem, uncertainties of their values and assessment of their mutual importance. The safety of the ship shall be presented in a simple and immediate manner in order to provide a useful decision support to onboard personnel. That is why a hierarchical risk assessment procedure has been developed selecting a set of attributes which are grouped in criteria and sub-criteria. The attributes are fuzzified and combined in order to obtain a risk index for each sub-criterion and criterion. The mutual importance of criteria, sub-criteria and attributes is assessed by means of a Fuzzy Analytical Hierarchical Process (FAHP), which rationally incorporates and treats the experience of masters and officers collected by a survey. This process allows summarizing experience and proficiency into a decision support system devoted to increase ship safety, while providing an interesting representation of the onboard perception about risk and its main causes.