Efficient scheduling of large vessels entering and leaving ports is critical to improving port efficiency, particularly for ports affected by tidal constraints. This study investigates the ship scheduling problem in tide-influenced ports, incorporating tidal window constraints while accounting for berth size differences, vessel safety distances, and mooring／unmooring operations. A Mixed-Integer Linear Programming (MILP) model is developed with the objective of minimizing the total delay time of all vessels, and a Lagrangian relaxation heuristic algorithm is designed for its solution. A case study using real tidal data from the Ningbo-Zhoushan Wai Diao operation area was conducted. The results show that the proposed scheduling model and algorithm, which consider tidal window constraints, can reduce vessel delays by 28. 5% while meeting safety requirements. This approach provides valuable insights for scheduling in ports significantly affected by tides.

Improving ship energy efficiency and reducing greenhouse gas emissions are major research priorities in the maritime industry. Accurate prediction of main engine power is fundamental to enhancing vessel energy efficiency. Using historical operational data collected from a Very Large Crude Carrier (VLCC), this study integrated and cleaned meteorological data to construct training and test datasets. Three models for main-engine power estimation are investigated and compared:a mechanistic model （SNNM), a non-mechanistic model based on Random Forest （RF), and a semi-mechanistic RF-based model. Simulation results indicate that while the mechanistic SNNM model can meet application requirements under specific engineering conditions, but R² coefficient is relatively low. In contrast, both the non-mechanistic model based on RF and the semi-mechanistic RF-based model demonstrated excellent predictive accuracy for both main engine shaft rotational speed and power, with R² values exceeding 0. 98.

In order to solve the complexity and uncertainty problems in the berthing process of large ships, this paper develops a decision support model based on Case-Based Reasoning (CBR). This model integrates CBR technology with a cloud model and BP neural networks. It comprehensively considers multi-dimensional attributes such as vessel characteristics, meteorological and hydrological conditions, and port factors to establish a case framework comprising a basic information domain, a characteristic attribute domain, and a decision support domain. By integrating expert scoring with the cloud model, the model processes the randomness and fuzziness in expert evaluations to optimize the case attribute weights. Furthermore, it utilizes BP neural network to achieve case reuse and decision prediction, thereby reducing subjective errors introduced by manual intervention. In this paper, we collect the berthing cases of Chiwan and Shekou container terminals at Shenzhen Port for model validation. The preliminary verification model can provide relevant decision support for pilots, expand new scenarios of artificial intelligence technology in maritime applications, and provide new ideas for intelligent berthing planning of unmanned ships.

This paper reviews the historical development, research progress, and major challenges of nuclear-powered civilian vessels, and further explores their developmental trends and potential application pathways. First, it outlines the historical evolution of three typical applications, namely nuclear-powered merchant ships, nuclear-powered icebreakers, and offshore floating nuclear power plants, and summarizes the current status of relevant standards, regulations, and regulatory frameworks. Secondly, this study systematically reviews the current international research progress on various technical routes such as pressurized water reactors, fast reactors, molten salt reactors, small modular reactors, and micro modular reactors, and analyzes their potential advantages in civilian ship applications, as well as their limitations in terms of safety, economy, and regulation. Finally, the paper forecasts trends towards miniaturization, modularization, and inherent safety, and suggests steady progress through land-based testing, demonstration operations on fixed routes, segmented push-tug shipping modes, focused application scenarios, with the goal of improving economic efficiency and regulatory framework refinement.

With the implementation of the "2024-2025 Energy Conservation and Carbon Reduction Action Plan", the port industry, as a core component of the transportation system, faces urgent tasks in energy conservation and emission reduction. To enhance the carbon emission efficiency and competitiveness of regional port clusters, and to promote more sustainable development of port clusters in the Bohai Rim region, this study measures the carbon emission efficiency and dynamic efficiency of 14 major ports in the Bohai Rim from 2007 to 2022 using the unexpected output super-efficiency SBM-Malmquist model. A Tobit regression model is further constructed to analyze the influencing factors of port carbon emission efficiency. The results reveal an overall upward trend in carbon emission efficiency among Bohai Rim ports. The regional ranking of carbon emission efficiency has shifted from Shandong > Liaodong > Jingjinji to Jingjinji > Shandong >Liaodong, with the efficiency gap between Jingjinji and the Shandong and Liaodong Peninsula ports widening. Scientific innovation and ecological compensation are identified as primary drivers of port carbon emission efficiency improvement, while the level of openness, transport capacity, and industrial structure exert negative effects. Based on these findings, this paper proposes pathways for improving carbon emission efficiency and optimizing management in Bohai Rim port clusters.

To accommodate the complex operating conditions of inland waterway vessels and address the needs for green and intelligent development in the shipping industry, this paper proposes a comprehensive evaluation method for selecting ship propulsion schemes based on the entropy weight method and TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution)-Grey Relational Analysis （GRA). The power required for ship propulsion is estimated using the fundamental theory of ship-engine-propeller matching. Based on this, the power of the propulsion system and the selection and configuration of four power and propulsion schemes during actual ship navigation are determined. An evaluation index system is established for ship propusion options, in which the weight of each indicator is determined by the entropy weight method. The four power and propulsion schemes of an inland bulk carrier are then comprehensively evaluated using the TOPSIS and GRA. The results indicate that scheme 4 （diesel-gas-electric hybrid propulsion) performs best among the alternatives. The findings of this study can provide a reference for the selection of propulsion schemes for efficient and green ships.

This paper aims to introduce the fundamental content, legislative purpose, and implementation pathways of Korea's "Act on Promoting the Development and Commercialization of Autonomous Ships." It delves into an in-depth analysis of the measures taken to promote the research, development, and commercialization of autonomous surface ships, the regulatory framework and foundational systems established, as well as the intrinsic logic and practical as well as long-term significance underlying these aspects. By sharing Korea's basic practices in promoting cutting-edge maritime technological innovation through legislation and driving the development of smart shipping via commercialization, this paper seeks to provide valuable references for China's related legislative efforts, the acceleration of smart shipping development, and the advancement of its transport sector.

This article focuses on the significant revisions to the time limit system in the new Maritime Code of China, systematically examining the institutional restructuring in four key areas: the one-year time limit for the carriage of goods by sea, the recourse time limitation, special causes for the interruption of maritime time limitations, and the commencement of the time limitation for marine insurance claims. The research shows that the new Code has made important progress in maintaining the internationally accepted one-year benchmark, constructing a balanced bilateral time limit structure, appropriately broadening the causes for interruption, and unifying the commencement standard for insurance claims, thereby significantly enhancing the legal system's certainty and international harmonization. However, the new Code might face challenges in local adaptation, including the absence of an agreement-based extension mechanism, limited recourse time limitation relief space, and unclear special rules for liability insurance and subrogation. By analyzing the new legal system and evaluating its effectiveness and potential limitations, this article aims to provide response strategies for the shipping industry and judicial practice, promoting the continuous optimization of China's maritime legal environment.

The continuous increase in crisscross navigation between passenger and cargo ships poses a significant threat to navigation safety in restricted inland waters. Traditional row-by-row crossing operation methods are inadequate for ships navigating such complex environments, leading to a surge in navigational risks. This study proposes an enhanced row-by-row following ship crossing operation method, building upon traditional approaches to address the dual peak periods of passenger ship departures and tidal effects. Based on traffic conflict technology and dynamic ship domain theory, large-angle and small-angle row-by-row following ship crossing models were developed. The advantages of the proposed methods are validated using actual Automatic Identification System (AIS) data collected from the turnaround area of the busy Huangpu River. Results indicate that both the large-angle and small-angle row-by-row crossing methods effectively mitigate the safety limitations of traditional methods. Furthermore, the small-angle row-by-row crossing method improves passenger ship crossing efficiency by up to 50% compared to the large-angle method. The proposed row-by-row following vessel crossing operation method demonstrates significant potential for enhancing navigation efficiency and safety in restricted inland waterways, particularly in congested turnaround areas.

Currently, ship navigators can assess flow patterns using basic instruments and adjust maneuvering strategies accordingly. Access to detailed flow field data of a waterway can provide valuable information and early warnings for ships transiting the area. This study analyzes surface flow in the waters near Jianghan Bridge, captured by video. By employing Large-Scale Particle Image Velocimetry (LSPIV), a method is developed to measure surface flow velocity in the navigation channel, enabling analysis of surface flow characteristics and acquisition of surface flow field data. The obtained flow field data are validated through comparison with optical flow methods and Acoustic Doppler Velocimetry. Results demonstrate that the proposed surface flow velocity measurement method can effectively capture detailed flow pattern characteristics of surface currents in the study area. This approach provides data support for navigation and path planning of both conventional ships and smart ships utilizing big data, contributing practical value to the enhancement of maritime safety and operational efficiency.