The impact of safety factors on decision-making in maritime navigation

Approximately 85% of maritime accidents are accounted for by navigation accidents, caused by human errors such as mistakes in impropriate decision-making. Decision-making skills are the key to safe sailing. However, the assessment of decisionmaking based on objective measurements is rarely studied. This paper aims to assess the impact of safety factors on decision-making in maritime navigation. Two different levels of complexity, each with a different number of safety factors, were designed for the experiment. NASA-TXL rating was used to evaluate the participants’ perceived workload and performance, while objective measures such as deviation from the planned route were used to analyze decision-making and performance. Results indicate that a higher workload and stress level are associated with more complex scenarios and safety factors and that safety is prioritized in decision-making under stress. The research can be used to improve decision-making skills in maritime training programs

Coordinate Conversion and Switching Correction to Reduce Vessel Heading-Related Errors in High-Latitude Navigation

Considering the distortion errors of projected coordinates and the switching property of vessel heading, coordinate conversion and switching correction methods are proposed to modify a kinematic motion model and the Unscented Kalman Filter (UKF). The coordinate conversion method utilizes the grid convergence from a Universal Transverse Mercator (UTM) projection to correct the vessel heading. The switching correction is embedded in the UKF so that the innovations of vessel heading can be calculated correctly. The simulation results demonstrate that the proposed modifications in both model and algorithm can generate more accurate estimated vessel states from two simulated maneuvers. Since a reliable estimation of vessel maneuvers is the prerequisite in many intelligent systems that support various decision-making processes in maritime transportation, the proposed modifications can be therefore implemented into these systems to support navigation safety in high latitude areas

Maritime Security and Threat Assessments

Maritime security is still a challenge in international trade. In this case‐study we analyze how the Norwegian Shipowners’ Mutual War Risks Insurance Association (DNK) provides Norwegian maritime companies with regional assessments of threat‐levels. Through a survey and a series of interviews, we study factors that affect the communication and perception of threats, in addition to how maritime companies make security decisions regarding operating in different areas. The study concludes that the DNK and maritime companies largely have a common assessment of threat levels. Though communication between DNK and its member companies has challenges, the members largely consider DNK threat assessments to be reliable. Security decisions in maritime companies typically involve multiple actors, considerations of economy versus security, and multiple sources of security intelligence information

Localized advanced ship predictor for maritime situation awareness with ship close encounter

The marine navigation environment can become further complex when ships with different autonomy levels are introduced. To ensure navigation safety in such a mixed environment, advanced ship predictor type technologies are essential in aiding ship navigators to attain the highest levels of situation awareness (SA). Consequently, precise ship trajectory prediction, specifically within a short prediction horizon, should be included in such predictors as an indispensable component. This study introduces two methods for ship trajectory prediction on a local scale: the kinematic-based method and the Gate Recurrent Unit (GRU)-Pivot Point (PP)-based method. The first method utilizes kinematic motion models to predict a ship trajectory. In the second method, the GRU is trained to generate the predictions of related ship navigation states. The ship's PP is then extracted from these predicted states, subsequently providing the predicted ship trajectory. Both methods are validated using simulated maneuvering exercises to assess their effectiveness, with a prediction horizon of 90 s. The results show that the kinematic-based method excels in the predictions during ship's stable stages, i.e., steady-state conditions. Meanwhile, the GRU-PP-based method exhibits robust performances in cases when new rudder orders are executed, i.e., transient conditions. It is considered that these applications can provide significant benefits in maritime SA in present and future ship navigation

Development and Validation of a Safety Leadership Self-Efficacy Scale (SLSES) in Maritime Context

Extensive studies have highlighted the importance of leadership on safety in the maritime industry. However, current research lacks empirically tested theoretical models with valid and reliable scales for describing and measuring safety leadership in ship operations. This study reports the development and validation process of the first Safety Leadership Self-Efficacy Scale (SLSES) for assessing shipboard officer’s efficacy in exercising leadership for safety in merchant shipping. The research has been divided into three stages, including a content validation study (20 subject matter experts), an Exploratory Factor Analysis (EFA) (n = 150) and a Confirmatory Factor Analysis (CFA) (n = 396). The results have supported a higher order factor structure with three subscales – motivation facilitation, safety management and safety initiative – contributing to the measurement of safety leadership self-efficacy. The resulting scale has revealed adequate measurement properties with good explanatory power, construct validity and high internal reliability (Cronbach’s α = 0.971). SLSES can provide maritime researchers, practitioners and shipping organizations with a tool to assess and enhance safety leadership potentials of current and future shipboard officers. The theoretical, methodological and practical implications of SLSES were discussed