Abstract
This study examines the impact of physical and mental health conditions of officer of the watch (OOW) on marine accidents such as collisions and groundings. The research highlights the critical role of psychosocial factors, especially stress, burnout, and mobbing, in the occurrence of accidents. A Fuzzy Bayesian Network (FBN) based model was developed to quantitatively assess the effects of mental and physical health factors on marine accidents. Expert opinions were integrated into the model by converting linguistic uncertainties into probabilistic values using fuzzy logic. The subjective probabilities were elicited from 3 domain experts with backgrounds in maritime accidents, seafarers' mental and physical health, and human factors. The results indicate that mental health-related issues increase the risk of accidents approximately 2.5 times more than physical health problems. Factors such as stress, burnout, and mental fatigue significantly impair decision-making, situational awareness, and communication. In contrast, the impact of physical fatigue due to long working hours, shift-based operational schedules, and lack of sleep was found to be moderate. The study demonstrates that physical measures alone are insufficient for maritime safety; a holistic approach that includes psychological support, workload management, and mental health assessments is necessary. The proposed FBN model realistically captures the complex effects of human factors, offering innovative contributions to accident prevention strategies.