A ship's grounding appears to be a significant threat to the safety of its crew, marine environment and the local ports economy. The risk of such incidents is higher in rivers since weather conditions can significantly alter the depths of channels from those shown on navigation charts. By means of a fuzzy analytic hierarchy process, a new methodology is proposed, capable of evaluating the hazards of a ship's grounding in a river. The proposed method contributes to safe navigation in rivers. Navigators are able to assess grounding risk in a river passage based on local information of past incidents. The proposed methodology is used to evaluate commercial risks from groundings in the Parana River. A case study was carried out using data from 118 cases, as provided by local agencies for the period 2008–2017.

Arctic shipping routes attract more and more attention because of the increasing possibility to build commercial shipping routes which connect East Asia and Western Europe. To build profitable commercial shipping routes, shipping companies should study many issues about the Arctic carefully since it is a new and unfamiliar frontier. To find out key factors influencing the building of Arctic shipping routes, the authors applied the fuzzy Analytic Hierarchy Process (AHP) model in this study. Based on the AHP experts’ questionnaires, we applied the fuzzy AHP model to analyse the opinions of respondents. This article presents the results of an empirical survey conducted among shipping companies and academic researchers with ship captain experience to explore their attitudes toward the building of Arctic shipping routes. The findings showed that: ‘Safety and risk’ is the most important aspect affecting the building of Arctic shipping routes and in order of relative importance, the top six critical assessment factors are ‘navigation safety and risk analysis,’ ‘governance and cooperation,’ ‘navigation information,’ ‘cargo sources,’ ‘cost,’ and ‘navigator ability,’ respectively.

The Istanbul Strait is a challenging waterway for maritime traffic due to its rough topology, moderate to severe environmental conditions, and heavy local traffic. In particular, a total of 232 maritime accidents took place there between 2000 and 2011. In this study, generic fuzzy analytic hierarchy processes were used to assess the risk perception of stakeholders in the Istanbul Strait, including ship captains, maritime pilots and Vessel Traffic Services operators. These risk perceptions were then compared to the statistical maritime accident data, revealing a fundamental discrepancy between the risk perception and statistical data. Specifically, the area of the Straight with the highest number of accidents is perceived as relatively low-risk, whereas areas perceived as high-risk experience a lower number of accidents. Our results have implications for stakeholders as well as government agencies responsible for the safety of the Straight.