Augmented reality (AR) has potential for increasing safety in marine navigation, but current-generation AR devices have significantly limited field-of-view, which could make them impractical for such usage. We developed a virtual reality ship simulator that displays AR navigation overlays across variable fields-of-view. This paper presents a human factors study, in which participants (including experienced boaters) piloted a virtual vessel while navigating using combinations of a traditional electronic chart display and AR overlays presented at various fields-of-view. Eye movements were tracked to discover how AR and restricted fields-of-view effect navigational target finding, safety, and situational awareness. The results indicate that AR provides significant benefits that can promote safer marine navigation, and that the field-of-view of an AR device has some significant and predictable effects on its usefulness for navigational tasks. Increasing field-ofview capabilities in future AR hardware is expected to improve AR’s usefulness for marine navigational tasks, however, this research shows that current-generation AR hardware (such as HoloLens 2) may already be suitable for this application, as most of the significant benefits were gained by providing AR overlays regardless of their field-of-view.