Abstract With recent advances in autonomous navigation technology, the importance of ship maneuvering models that can predict maneuvering motions with high accuracy and interpretability has increased. This study proposes a hybrid maneuvering model for predicting ship motions using the Maneuvering Modeling Group (MMG) model and the Feedforward Neural Network (FNN). In the proposed model, the modular structure of the MMG model is enhanced through the addition of a complementary FNN module. This approach improves the prediction accuracy while maintaining the interpretability of the model. Furthermore, to prevent the FNN output from depending too heavily on its training data, an output constraint and a mechanism for detecting Out-of-Distribution (OOD) based on k-Nearest Neighbors (kNN) distance are introduced. Numerical verification using multiple maneuvering test datasets demonstrates that the proposed model consistently exhibits higher prediction accuracy than both the MMG-only and the FNN-only models. Specifically, it attains an average reduction of 30–40% in Root-Mean-Squared Error (RMSE) compared to the MMG-only model. In particular, under highly nonlinear maneuvering conditions, such as Turning test and Random maneuver, the model shows up to a 70% RMSE reduction. Additionally, the model exhibits low accuracy degradation over long-term predictions, ensuring stable motion predictions. Based on these results, the proposed hybrid model successfully integrates the characteristics of physical models and data-driven models, providing a practical maneuvering model that offers high accuracy, lower data dependency, and interpretability. This model offers a valuable foundation for applications in autonomous navigation support systems.

Abstract PULSE is an algorithm for multi-agent centralised maritime traffic management that utilises a novel approach to solve polymatrix games through evolutionary dynamics. Polymatrix games are graph-based, succinct game representations with asymmetric two-player normal-form games defined on the edges. Based on the vessels’ (players’) estimated trajectories, the proposed algorithm outputs sequences of pure strategy profiles in the form of speed and heading setpoint pairs, one for each player. These are pure Nash equilibria or their approximations intended for broadcast by the central coordinator. In maritime traffic management, vessel traffic services can provide navigational assistance and decision support to vessels via route suggestion. Guidance games , in which the payoff entries are bound to one, arise from a custom reward framework designed to govern how players balance the trade-off between externalities and internal preferences. We evaluate two variants of payoff calculations: a traditional one, where payoff vectors are derived using ordered player selection, and a novel one based on a random asymmetric two-player game selection. Given the preset strategy competition time, the latter approach reduces the equilibria search time dependency on the number of players from exponential to polynomial, making it more suitable for real-time applications compared to previous work. The simulations of consecutive guidance games and their 2-simplex visualisations highlight the structural properties of the resulting games, though a complete classification within game theory remains an open challenge. Inspired by distributed consensus-seeking algorithms, PULSE is a game-theoretical, multi-agent simulation-based model predictive control planner.

In this study, we conducted turning tests with rudder angles ±35∘ and ±20∘/20∘ zig-zag maneuver tests in deep and shallow water using a model of a 3,600 TEU container ship called KCS. Through the comparison of these test results with the free-running test results of three other ships, the shallow-water effect on the maneuverability was investigated. The shallow-water effects obtained during the turning and zig-zag maneuvers are as follows: Turning: The advance (AD) decreases slightly when the water depth-to-ship draft ratio (h/d) is approximately 2.0 and increases significantly as the water depth decreases. The tactical diameter (DT) (up to h/d=2.0) is approximately the same as that in deep water and becomes significantly larger when h/d becomes smaller than 2.0. Thus, there is a slight difference in the appearance of the shallow-water effects in AD and DT. Zig-zag maneuvers: The overshoot angle increases slightly near h/d=2.0 compared with that in deep water and becomes significantly smaller as the water depth becomes shallower. The forward distance (l20), until reaching the heading +20∘/-20∘ after steering, was approximately the same as that in deep water or decreased slightly, until approximately h/d=2.0. Furthermore, it increased as the water depth decreased. This is because the course stability of the ship deteriorated at approximately h/d=2.0.

The International Maritime Organization (IMO) has formulated numerous maritime-related conventions. The promotion of mandatory audits is required to ensure that the implementation of maritime management systems in various countries complies with the IMO Instruments Implementation Code (III Code) and that both member states and non-member states implement these conventions. This is not only an obligation but also a responsibility for all countries to promote the development of the maritime industry. This study investigates how Taiwan, one of the non-member state of the IMO, implements the audit process and develops future implementation strategies for various maritime conventions. This issue is of great significance to Taiwan as an important hub in the international maritime industry. The results of the study reveal that the proactive efforts of government authorities and officials and active participation in audits are considered the most crucial driving factors by most experts. However, more attention should be given to the challenging issues associated with international participation, which currently represent external threats and internal weaknesses. Furthermore, the continuous and proactive participation in audits of relevant IMO regulations is a key strategy for non-member states to maintain long-term strength in the maritime industry. Other non-member states can also refer to Taiwan's experience, strive to keep up with international standards, and seek to join the IMO to contribute to global maritime efforts. In addition, Taiwan’s government should make better use of and continue to support Taiwan’s maritime industry and strong private sector. Moreover, cooperation with international allies is a critical strategy for completing audits and sustaining the development of Taiwan’s maritime industry.

Trapping is a primary fishing method to capture swimming crab species along the coast of Vietnam, because it has low ecological and environmental impacts. In trap fisheries, bait plays a primary role in determining the effectiveness of the gear and is one of the largest operational costs. Fishermen determine bait types based on their experience and what they can find, where trash fish caught by trawl fisheries is preferred and commonly used. However, the catch rates of swimming crab traps are typically low and highly variable and thus, there is considerable interest to improve the catchability. This study examined the catch efficiency of commercial swimming trap fishery using new bait types against traditional trash fish bait. Of the six types of experimental baits investigated, channeled applesnail (Pomacea canaliculata) was associated with significant reductions in catch rates; splendid ponyfish (Leiognathus splendens), by-products from seafood processing, and largehead hairtail (Trichiurus lepturus) showed no statistically significant difference in catch per unit effort (CPUE, number of crabs per trap) of all swimming crab species compared to trash fish bait (control bait). Finally mixed trash fish–squid (Loligo chinensis) and only squid significantly increased catch rates of crabs. Besides the channeled applesnail catching less crab than the control bait for all size classes, there was not a clear pattern for the size comparison between experimental baits and control bait for all three tested species. This study shows that crab fishing industries can improve the catching performance by using effective bait and that there are more options for fishermen to select bait types for their trap fisheries.

With the rapid development of the global economy, international imports and exports have become increasingly important. Timely and effective tracking and prediction of ship trajectories are important in the face of complex maritime traffic. Based on AIS data, this study establishes a ship trajectory prediction model combining improved particle swarm optimization (IPSO) and a convolutional neural network (CNN) that uses the ship's historical navigation trajectory data to predict the future navigation trajectory. The historical ship trajectory data of the Port of Ningbo-Zhoushan were selected for the experiment, and the IPSO-CNN model experiment results were compared with those of other models. According to the experimental results, the IPSO-CNN model exhibited good performance and high prediction accuracy. The prediction trajectory is more fitting with the real route, and the error is less than 0.001, which is reduced by 57.54% compared with the original CNN model, and the prediction accuracy is higher. Therefore, IPSO-CNN is well-suited for predicting ship trajectories and can achieve accurate prediction. They play important guiding roles in future ship hazard warnings, ship anomaly monitoring, and other applications.