This article presents research on how frequently seafarers utilise functions and information available on an Integrated Navigation System to perform navigation duties. Using an online questionnaire, the study collected data from 601 members of the global seafaring community. The results provide an overview of the frequency of use for each feature, together with factors affecting the use and associated usability issues. The study finds that the use of navigation equipment is situation-dependent and affected by administrative factors, experience and professional habits, characteristics of the sailing area, traffic conditions, weather conditions, ship management factors and geographical location. Additionally, information overload, particularly with overlay and alert management functions, was found to be the major issue with existing systems. The findings of this study can be applied to improve menu tree structure, display layout, and interaction methods on the interface of navigation systems, such as making frequently-used features more readily available or easier to access.
