Journal of Marine Science and Engineering

31 pages, 16185 KB

Open AccessArticle

Machine-Learning-Assisted Prediction of Port-Flow Distribution and Multi-Objective Parametric Optimization for Navigation Lock Manifolds

by Duo Xu, Zhonghua Li, Lingqin Mei and Tingqiang Xie

J. Mar. Sci. Eng. 2026, 14(14), 1275; https://doi.org/10.3390/jmse14141275 - 10 Jul 2026

Abstract

Navigation lock manifolds are key components of filling-and-emptying systems, and port-flow distribution affects chamber flow stability and filling efficiency. Under unsteady filling conditions, port-flow distribution is governed by discharge variation and manifold geometry, making rapid prediction and engineering-constrained screening challenging. This study develops [...] Read more.

Navigation lock manifolds are key components of filling-and-emptying systems, and port-flow distribution affects chamber flow stability and filling efficiency. Under unsteady filling conditions, port-flow distribution is governed by discharge variation and manifold geometry, making rapid prediction and engineering-constrained screening challenging. This study develops a surrogate-assisted prediction and Pareto-screening framework for a large-scale navigation lock manifold. Three-dimensional computational fluid dynamics (CFD) simulations were used to examine unsteady port-flow evolution. The peak-flow condition was selected as a representative control condition, and the flow non-uniformity coefficient α and system resistance coefficient ξ were used as performance indicators. Based on 243 parametric CFD samples and 144 independent external test samples, artificial neural network (ANN), Gaussian process regression (GPR), and support vector regression (SVR) models were evaluated. ANN performed best, with independent-test R² values of 0.9999 and 0.9928 for α and ξ. Feature-attribution analysis identified port width, culvert height, and port number as dominant variables. Pareto screening within a predefined engineering design space identified representative candidates with CFD verification errors below 1.1%. The TOPSIS-based candidate reduced ξ by 32.2% while maintaining α nearly unchanged. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

24 pages, 6614 KB

Open AccessArticle

DTMB-5415 Hydrodynamic Derivative Estimation Through Oblique Towing CFD Simulations

by Paolo Curtolo, Simone Mancini and Ermina Begovic

J. Mar. Sci. Eng. 2026, 14(14), 1274; https://doi.org/10.3390/jmse14141274 - 10 Jul 2026

Abstract

Numerous studies have focused on Computational Fluid Dynamics (CFD) Unsteady Reynolds-Averaged Navier–Stokes (URANS) maneuvering simulations of benchmark ships such as the David Taylor Model Basin (DTMB) 5415 model. However, the availability of hydrodynamic derivatives obtained from verified and validated simulations at Froude numbers [...] Read more.

Numerous studies have focused on Computational Fluid Dynamics (CFD) Unsteady Reynolds-Averaged Navier–Stokes (URANS) maneuvering simulations of benchmark ships such as the David Taylor Model Basin (DTMB) 5415 model. However, the availability of hydrodynamic derivatives obtained from verified and validated simulations at Froude numbers (Fr) of 0.41 remains limited. In this study, CFD-URANS oblique towing simulations are conducted for the DTMB 5415 benchmark hull at Fr = 0.41 and Fr = 0.28 using STAR-CCM+. Verification and validation are performed according to ITTC guidelines for Fr = 0.41 and a drift angle of 10 degrees. The validation criterion is satisfied for the longitudinal force, side force, and yawing moment, with validation uncertainties of 13.5%, 2%, and 4%, respectively. The resulting forces and moments are fitted to derive a partial set of hydrodynamic derivatives. The CFD results are compared with SIMMAN workshop (2008) Experimental Fluid Dynamics (EFD) data, showing higher prediction accuracy for linear derivatives. At Fr = 0.41, the relative errors of Y’_V and N’_V are approximately 3% and 4%, while at Fr = 0.28, they are approximately 2% and 5%. Nonlinear components exhibit discrepancies exceeding 15%. Hydrodynamic coefficients show different dependencies on Fr, consistent with previous studies. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

27 pages, 9083 KB

Open AccessArticle

Beyond Inflation: Backscatter Parameterizations to Address the Variability Deficit in Global Ocean Data Assimilation

by Kate Boden, Daniel E. Amrhein, Jeffrey L. Anderson, Frederic S. Castruccio, Mohamad El Gharamti and Ian Grooms

J. Mar. Sci. Eng. 2026, 14(14), 1273; https://doi.org/10.3390/jmse14141273 - 10 Jul 2026

Abstract

Global ocean models at non-eddying resolutions currently used for subseasonal to seasonal to decadal (S2S2D) prediction suffer from a severe deficit in internal variability. In ensemble data assimilation (DA), this can lead to under-dispersed ensembles that require inflation schemes. However, inflation corrections do [...] Read more.

Global ocean models at non-eddying resolutions currently used for subseasonal to seasonal to decadal (S2S2D) prediction suffer from a severe deficit in internal variability. In ensemble data assimilation (DA), this can lead to under-dispersed ensembles that require inflation schemes. However, inflation corrections do not persist into the forecast phase, causing ensemble spread to collapse at longer lead times. This study evaluates an alternative approach: addressing the variability deficit directly within the model physics using a “Backscatter Package” (BackPack) consisting of the stochastic Stanley, stochastic GM+E, and Leith+E backscatter parameterizations. Implemented within a global MOM6/CESM framework at nominal

2 / 3 °

resolution using the DART ensemble DA package, the BackPack’s impacts are compared against cutting-edge adaptive inflation. The results demonstrate that the BackPack substantially increases internal variability and ensemble spread, successfully lowering the amount of required inflation. While reductions in ensemble-mean state errors are modest, the BackPack significantly improves ensemble calibration, assessed using a novel spread–error calibration ratio metric. Although this study only addresses the data assimilation phase, we expect that physics-based BackPack schemes may provide a physically sustainable pathway to maintain spread during the subsequent forecast phase. Full article

(This article belongs to the Special Issue Marine Modelling and Environmental Statistics—2nd Edition)

► Show Figures

Figure 1

25 pages, 2024 KB

Open AccessArticle

Research on Dynamic Positioning Methods of Unmanned Surface Vehicles Applied to Algae Removal

by Baoqiang Tian, Zhiqiang Zhang, Yuntian Qin, Jibo Chen and Linjian Shangguan

J. Mar. Sci. Eng. 2026, 14(14), 1272; https://doi.org/10.3390/jmse14141272 - 10 Jul 2026

Abstract

Excessive proliferation of algal organisms can severely affect water quality and ecological security. Traditional algae removal techniques, including physical, chemical and biological methods, generally exhibit shortcomings such as long algae removal cycles and impact on water quality, and they cannot meet the algae [...] Read more.

Excessive proliferation of algal organisms can severely affect water quality and ecological security. Traditional algae removal techniques, including physical, chemical and biological methods, generally exhibit shortcomings such as long algae removal cycles and impact on water quality, and they cannot meet the algae removal needs of large-scale flowing water areas in the South-to-North Water Diversion Project (SNWDP). This study addresses the key technical challenges in algae removal operations on the slopes of the SNWDP, and an integrated algae removal solution based on an unmanned surface vehicle (USV) platform is proposed. This solution offers advantages such as high automation, notable adaptability, efficient algae removal, and minimal impacts on water quality. To mitigate environmental disturbances caused by wind, waves and currents, and enhance the accuracy and efficiency of USV operation, a dynamic model of a USV as a controlled object is first established, and an adaptive backstepping sliding mode control (ABSMC) algorithm for its dynamic positioning is proposed. Through numerical simulation and comparative analysis under different conditions, the effectiveness of the designed control algorithm is validated, and key parameters are optimized. The proposed control algorithm facilitates fast and accurate dynamic positioning and trajectory tracking, thereby enhancing the precision and efficiency of the USV platform in algae removal operations. Full article

(This article belongs to the Section Ocean Engineering)

24 pages, 4398 KB

Open AccessArticle

Context-Dependent Control of Erosion Resistance in Intertidal Flats: The Central Role of Bulk Density Across Natural and Restored Systems

by Rafaela Paulo Teixeira, Laura Bossaer, Gregory S. Fivash, Tim Grandjean, Jim van Belzen, Johan van de Koppel, Stijn Temmerman, Tjeerd J. Bouma and Brenda Walles

J. Mar. Sci. Eng. 2026, 14(14), 1271; https://doi.org/10.3390/jmse14141271 - 10 Jul 2026

Abstract

Intertidal flats are highly dynamic coastal environments that provide vital ecosystem services. Despite their importance, intertidal flats are declining worldwide. In response, a range of restoration and management measures are increasingly being applied to enhance sediment accumulation and stabilize the bed surface. However, [...] Read more.

Intertidal flats are highly dynamic coastal environments that provide vital ecosystem services. Despite their importance, intertidal flats are declining worldwide. In response, a range of restoration and management measures are increasingly being applied to enhance sediment accumulation and stabilize the bed surface. However, the effectiveness of these interventions ultimately depends on how sediment properties and bed stability develop over time. Quantitative understanding of these properties in natural and restored intertidal areas remains limited because field measurements are scarce, spatial heterogeneity is high, and hydrodynamic forcing is highly variable. Here, we quantify differences in key sediment properties between natural and restored intertidal flats to identify bed stability. We sampled sediments and measured key in situ bed characteristics at 16 intertidal sites in the Dutch Eastern and Western Scheldts, spanning multiple restoration strategies (i.e., managed realignments, groynes, and sediment nourishments) and natural locations. Our results show that restoration sites differ in sediment characteristics, with bulk density as the most consistent predictor of critical shear stress, an indicator of bed stability. These findings provide new insights into erosion thresholds in intertidal environments and can help inform adaptive coastal management of restoration measures under accelerating intertidal loss. Full article

(This article belongs to the Special Issue Linking Sedimentary and Erosive Processes with Morphodynamics in Coastal Zones)

► Show Figures

Figure 1

20 pages, 9981 KB

Open AccessArticle

Equivalent Nodal Force Versus Thermal Load in Nonlinear Welding Distortion Analysis of Stiffened Panels

by Juneyoung Kim, Youngkyun Seo and Jaemin Lee

J. Mar. Sci. Eng. 2026, 14(14), 1270; https://doi.org/10.3390/jmse14141270 - 10 Jul 2026

Abstract

Accurate prediction of welding-induced deformation is essential for dimensional control in large-scale ship block construction. In production design, transverse shrinkage directly governs the cutting allowance and shrinkage margin among various deformation modes. The inherent strain framework is widely used due to its computational [...] Read more.

Accurate prediction of welding-induced deformation is essential for dimensional control in large-scale ship block construction. In production design, transverse shrinkage directly governs the cutting allowance and shrinkage margin among various deformation modes. The inherent strain framework is widely used due to its computational efficiency, but the interaction between the implementation of equivalent loads and geometric nonlinearity has not been systematically investigated. This study evaluates two conventional loading representations: the equivalent nodal force method and the equivalent thermal load method, under both linear and geometrically nonlinear analysis formulations. In linear elastic analysis, both representations are equivalent and successfully provide identical, stable in-plane shrinkage predictions because both methods utilize input loads formulated from the same target inherent deformation. However, in shipbuilding practice, a geometrically nonlinear formulation is frequently required to capture large-displacement behaviors or structural instabilities in thin-walled assemblies. When geometric nonlinearity is introduced into these shrinkage predictions, a critical discrepancy emerges depending on the load implementation: the equivalent nodal force method violates the physical basis of shrinkage prediction by introducing unwanted out-of-plane deformation artifacts. This is a numerical artifact arising from the interaction of localized artificial compressive stresses with the stress-dependent geometric stiffness matrix. In contrast, the equivalent thermal load method is robust and always preserves the target in-plane shrinkage without any undesired out-of-plane geometry. Therefore, even though both methods are robust in the linear regime, the equivalent thermal load method is recommended when a geometrically nonlinear formulation is involved to ensure numerical consistency and reliability in production design. Full article

(This article belongs to the Special Issue Structural Modelling, Safety Assessment, and Advanced Material Application of Marine Structures—2nd Edition)

► Show Figures

Figure 1

38 pages, 4660 KB

Open AccessReview

Offshore Floating Photovoltaics in China: Structural Concepts, Hydrodynamic Challenges, and Future Perspectives

by Xianlin Jia, Su Guo, Kangjie Wang, Yong Zhao, Jinhui Du and Wei Peng

J. Mar. Sci. Eng. 2026, 14(14), 1269; https://doi.org/10.3390/jmse14141269 - 10 Jul 2026

Abstract

Offshore floating photovoltaics (OFPVs) offer a promising route for expanding solar energy development from land and inland waters to marine space, particularly in China’s coastal regions where electricity demand, land-use constraints, offshore wind infrastructure, and photovoltaic manufacturing capacity are highly concentrated. This review [...] Read more.

Offshore floating photovoltaics (OFPVs) offer a promising route for expanding solar energy development from land and inland waters to marine space, particularly in China’s coastal regions where electricity demand, land-use constraints, offshore wind infrastructure, and photovoltaic manufacturing capacity are highly concentrated. This review examines the development status, structural concepts, hydrodynamic challenges, research methodologies, reliability issues, and future pathways of OFPV systems in China from the perspective of marine engineering. Demonstration projects, representative platform concepts, and recent studies on environmental loading, platform motion, multi-body interaction, connector and mooring responses, and hydroelastic behavior are systematically synthesized. The review shows that Chinese OFPV technology has progressed from conceptual exploration to prototype testing and sea-based validation, with flexible membrane, steel-frame, semi-submersible, tensioned floating-island, HDPE modular, and composite-material concepts under active investigation. However, mature and replicable engineering solutions remain limited. Key barriers include survivability under extreme sea states, fatigue reliability of large arrays, corrosion, biofouling, material degradation, insufficient long-term field data, and the lack of dedicated design standards. Future development should emphasize array-level hydrodynamic design, coupled connector–mooring optimization, life-cycle reliability assessment, full-scale monitoring, and integration with offshore wind, wave energy, floating breakwaters, aquaculture, and other marine energy systems. Full article

(This article belongs to the Special Issue Offshore Renewable Energy: Waves, Tides, and Wind)

► Show Figures

Figure 1

18 pages, 1143 KB

Open AccessArticle

Influence of Mineral Loading Variations on the Body State of a Deep-Sea Mining Vehicle

by Yunjia Zhang, Zhangfeng Huang and Yangrui Cheng

J. Mar. Sci. Eng. 2026, 14(14), 1268; https://doi.org/10.3390/jmse14141268 - 9 Jul 2026

Abstract

Tracked deep-sea mining vehicles (DSMVs) interact strongly with soft seabed sediments during seafloor operations, which may cause excessive sinkage and vehicle instability. Variations in mineral loading and initial pitch angle are important factors affecting operational safety. In this study, the “Kunlong 500” tracked [...] Read more.

Tracked deep-sea mining vehicles (DSMVs) interact strongly with soft seabed sediments during seafloor operations, which may cause excessive sinkage and vehicle instability. Variations in mineral loading and initial pitch angle are important factors affecting operational safety. In this study, the “Kunlong 500” tracked DSMV was selected as the prototype, and a coupled Eulerian–Lagrangian (CEL) numerical model was established to simulate vehicle–sediment interaction. The Drucker–Prager elastoplastic model was adopted to describe sediment yielding and plastic deformation. Different mineral loading levels and initial pitch angles were considered to investigate vehicle sinkage, local Mises stress in the track–sediment contact region, and attitude response. The results show that increasing mineral loading significantly increases body sinkage and rear-track Mises stress, causing the vehicle response to evolve from overall sinkage to rear-biased sinkage. Under the present model parameters, the reference critical loading for local rear-track sinkage was estimated to be approximately 5.8 t, with a sensitivity range of approximately 4.5–7.1 t under ±10% variation in the equivalent bearing term. Under the present model conditions, loading conditions of 8 t and above should therefore be treated as key risk-control cases. The initial pitch angle further aggravates asymmetric sinkage, especially under the 4 t loading and 4° pitch condition. These findings provide a reference for load control and attitude regulation of DSMVs. Full article

(This article belongs to the Section Ocean Engineering)

25 pages, 2209 KB

Open AccessArticle

Optimisation of Nautical Anchorages: A Six-Method Hybrid Approach

by Danijel Pušić, Zvonimir Lušić and Mario Bakota

J. Mar. Sci. Eng. 2026, 14(14), 1267; https://doi.org/10.3390/jmse14141267 - 9 Jul 2026

Abstract

The increasing complexity of marine spatial management and the rapid growth of nautical tourism require the use of formal and transparent decision-making models. Identifying optimal locations for nautical anchorages is a multi-criteria decision problem (MCDP) in which navigation safety, spatial constraints, and environmental [...] Read more.

The increasing complexity of marine spatial management and the rapid growth of nautical tourism require the use of formal and transparent decision-making models. Identifying optimal locations for nautical anchorages is a multi-criteria decision problem (MCDP) in which navigation safety, spatial constraints, and environmental protection often conflict. This study presents an integrated framework combining Geographic Information Systems (GIS) and multi-criteria decision-making (MCDM) methods for the systematic evaluation and ranking of nautical anchorages. As a case study, 86 potential locations in Split-Dalmatia County, Croatia, were analysed based on 18 criteria encompassing hydrological, meteorological, and spatial factors, as well as risk factors relevant to navigation safety. The methodological approach applies six MCDM methods implemented in the R programming language: Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), ViseKriterijska Optimizacija I Kompromisno Rjesenje (VIKOR), Multi-Objective Optimisation on the Basis of Ratio Analysis (MOORA), Complex Proportional Assessment (COPRAS), Measurement of Alternatives and Ranking according to Compromise Solution (MARCOS), and Evaluation Based on Distance from Average Solution (EDAS). To reduce methodological bias, a final Consensus rank was calculated to synthesise the results of all applied methods. The stability of the obtained ranking was examined through an analysis of rank agreement between methods, using a diagonal matrix of rank overlaps and the corresponding heatmap visualisation. The results indicate a high level of consistency among individual MCDM methods and strong stability of the final consensus ranking. The proposed model ranks locations from best to worst based on how well they meet the established criteria, while ensuring strict navigational safety and compliance with environmental constraints. These findings confirm that the integrated GIS–MCDM approach is a reliable, repeatable, and scientifically grounded tool for supporting spatial planning and concession allocation in the development of nautical infrastructure. Full article

(This article belongs to the Special Issue Maritime Security and Risk Assessments—2nd Edition)

► Show Figures

Figure 1

22 pages, 1399 KB

Open AccessArticle

A Framework-Based Evaluation of Open Data Platforms in European Ports: A Comparative Study of Barcelona and Antwerp–Bruges

by Lucas Freitas, Ana J. Mendes, Marcela Castro and Tiago Pinho

J. Mar. Sci. Eng. 2026, 14(14), 1266; https://doi.org/10.3390/jmse14141266 - 9 Jul 2026

Abstract

Open data platforms (ODPs) are emerging as strategic infrastructures for smart port development within the European Union, yet there is limited research offering integrated approaches to evaluate their performance across technical, operational, and regulatory dimensions. To address this gap, this study develops an [...] Read more.

Open data platforms (ODPs) are emerging as strategic infrastructures for smart port development within the European Union, yet there is limited research offering integrated approaches to evaluate their performance across technical, operational, and regulatory dimensions. To address this gap, this study develops an analytical framework combining four complementary perspectives: open data platform design, FAIR (Findability, Accessibility, Interoperability, and Reusability) principles, smart port enablement, and EU regulatory alignment. The framework is applied through a qualitative comparative case study of the Ports of Barcelona and Antwerp–Bruges, based exclusively on secondary data sources, including the academic literature, policy documents, and publicly accessible platform data. The analysis is structured around three analytical dimensions—FAIR and interface features and accessibility, smart port enablement, and EU regulatory alignment—applied consistently across both cases. The findings reveal two distinct models: Barcelona adopts an open-by-default approach prioritising accessibility, transparency, and integration with public data ecosystems, while Antwerp–Bruges follows a controlled-access model focused on operational integration, system reliability, and business-to-business data exchange. Both approaches align with EU policy frameworks but involve different trade-offs between openness and operational control. The study contributes a structured, transferable framework for evaluating port ODPs and identifies practices for their design and governance in smart port and maritime logistics contexts. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

21 pages, 1084 KB

Open AccessArticle

Coral Reef Community Structure and Photophysiology Differ Between Upwelling and Non-Upwelling Locations on the Pacific Coast of Costa Rica

by Dar Golomb, Kayla M. Cayemitte, Grace K. Saba, Lori M. Garzio, Maxim Gorbunov, Clinton Haldeman, Juan José Alvarado, Tali Mass and Fiorella Prada

J. Mar. Sci. Eng. 2026, 14(14), 1265; https://doi.org/10.3390/jmse14141265 - 9 Jul 2026

Abstract

Reef-building corals and coralline algae form the calcium carbonate frameworks that underpin tropical coral reefs, yet in some locations, coral cover has declined by ~50% in recent decades due to marine heatwaves and other stressors. Identifying refugia environments, such as upwelling systems, that [...] Read more.

Reef-building corals and coralline algae form the calcium carbonate frameworks that underpin tropical coral reefs, yet in some locations, coral cover has declined by ~50% in recent decades due to marine heatwaves and other stressors. Identifying refugia environments, such as upwelling systems, that may buffer stress, promote recovery, and could enhance resilience by promoting physiological plasticity that supports thermotolerance is therefore critical. Here, we compared benthic community composition, coral percent cover, and photophysiology between an upwelling location in the Gulf of Papagayo and a non-upwelling location in Sámara on the Pacific coast of Costa Rica. Waters in Papagayo were cooler, more acidic, and had higher chlorophyll-a concentrations. Reefs at this location exhibited higher crustose coralline algae, higher sea urchin abundance, and lower macroalgae cover, compared to Sámara. Papagayo also showed higher stony coral cover, driven by Pocillopora spp., while Sámara was dominated by massive, heat-tolerant Porites spp. Photophysiological parameters were significantly different between locations. Specifically, photosynthetic efficiency (F_v’/F_m’) was 10–45% higher, and maximum photosynthetic rate (P_max) was 20–40% lower in corals from Papagayo than in those from Sámara. These results reveal that two locations differing in environmental regime within a relatively small geographic area also differ in coral community composition and photophysiological features. Although further research is needed to resolve whether these environmental contrasts shape the observed biological differences, the observed patterns are consistent with the hypothesis that such regimes may support reef persistence or refugia, providing a basis for future work to test this hypothesis directly. Full article

(This article belongs to the Special Issue Coral Reefs in a Changing World: Disturbance, Recovery, and Resilience)

24 pages, 47181 KB

Open AccessArticle

Toward Real-Time Shipwreck Detection for Autonomous Underwater Vehicles Using Deep Learning: A Model Evaluation Using High-Resolution Bathymetry Data

by Agno Rubim de Assis, Thomas Guilment, Marco D’Emidio and Leonardo Macelloni

J. Mar. Sci. Eng. 2026, 14(14), 1264; https://doi.org/10.3390/jmse14141264 - 9 Jul 2026

Abstract

Autonomous Underwater Vehicles (AUVs) equipped with multibeam echosounders (MBESs) are deployed in oceans in expeditions worldwide to find shipwrecks, as they can survey the seafloor at the resolution required to identify such objects. Due to the severely constrained acoustic bandwidth of underwater communication, [...] Read more.

Autonomous Underwater Vehicles (AUVs) equipped with multibeam echosounders (MBESs) are deployed in oceans in expeditions worldwide to find shipwrecks, as they can survey the seafloor at the resolution required to identify such objects. Due to the severely constrained acoustic bandwidth of underwater communication, it is fundamental to transmit compressed information between the AUV and the support vessel when objects of interest are detected during a mission. This paper presents a systematic evaluation of six YOLO-based configurations combining three architectures with two optimizers, along with selected hyperparameters and bathymetric visualization methods, to identify the optimal model for shipwreck detection suitable for deployment on a deep-water AUV. Such an application has the potential to optimize mapping operations, allowing the mission to be terminated early or to employ adaptive route replanning to maximize survey efficiency. We developed and evaluated an object detection model trained on high-resolution shallow-water open-source data, identifying over 630 shipwrecks along the coast of England to fine-tune the model. Six experiments were conducted and compared across the three most recent YOLO architectures by Ultralytics (v8, v11, v26) and specific hyperparameter configurations. The best-performing model achieved scores above 0.91 in precision, recall, F1, and mAP50, while successfully detecting all prominent shipwrecks in the dataset. Three additional models trained on different data visualizations (hillshade, color scale, shaded relief) demonstrated similar performance. The best-performing model was further tested on a small AUV dataset from the Gulf of America, where it successfully detected the shipwreck in deep-water. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

37 pages, 3186 KB

Open AccessArticle

OPA-Z: An Integrated Approach for Oil–Particle Aggregate Genesis, Settling, and Fragmentation

by Jacqueline Esimike, Michel Boufadel, Wen Ji and Kelly McFarlin

J. Mar. Sci. Eng. 2026, 14(14), 1263; https://doi.org/10.3390/jmse14141263 - 8 Jul 2026

Abstract

Oil–particle aggregate (OPA) formation, fragmentation, and settling govern the fate of oil that strands on sediment-rich shorelines, yet no publicly accessible, size-resolved software tool currently couples these three processes within a single population balance framework. Existing models either resolve OPA formation without breakup [...] Read more.

Oil–particle aggregate (OPA) formation, fragmentation, and settling govern the fate of oil that strands on sediment-rich shorelines, yet no publicly accessible, size-resolved software tool currently couples these three processes within a single population balance framework. Existing models either resolve OPA formation without breakup or resolve breakup from a prescribed initial distribution, forcing practitioners to chain tools manually. We address this gap by developing OPA-Z, a software tool whose kernel unifies (i) A-DROP coagulation/attachment, (ii) binary fragmentation and shell shredding, and (iii) an analytical advection–diffusion settling solution within a single discretized population balance model. The integrated kernel is wrapped in a graphical user interface (GUI) that enables non-expert scenario testing on a web-hosted application. Model inputs include oil properties (interfacial tension, viscosity, density), particle properties (sand, clay, mixtures, sizes, density), turbulence intensity, and water depth. Outputs include time-resolved OPA size distributions, oil trapping efficiency (OTE), oil-to-sediment ratio (OSR), and cumulative oil settled to the bed. The model operates in a pulse mode of oil release that simulates a slick arriving at the shorelines, representative of nearshore spill response scenarios such as beached oil remobilization or slick stranding events. Model fidelity is demonstrated by reproducing benchmark coagulation data in laboratory systems. The software is designed to integrate with GIS-based particle fields, supporting fast, transparent assessments of nearshore OPA fate to respond to oil spills and for contingency planning. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Graphical abstract

36 pages, 7562 KB

Open AccessArticle

A Hierarchical Multi-Source Condition Monitoring and Fault Diagnosis Framework for LNG Submersible Centrifugal Pumps in Marine Energy Transportation Systems

by Zemin Li, Kun Liu, Chongchong Guo and Wenhua Wu

J. Mar. Sci. Eng. 2026, 14(14), 1262; https://doi.org/10.3390/jmse14141262 - 8 Jul 2026

Abstract

Liquefied natural gas (LNG) submersible centrifugal pumps are critical components in marine energy transportation systems, and fault-induced degradation may threaten operational safety, transfer reliability, and maintenance efficiency. However, condition monitoring and fault diagnosis often rely on heterogeneous multi-source data, where redundant information, unequal [...] Read more.

Liquefied natural gas (LNG) submersible centrifugal pumps are critical components in marine energy transportation systems, and fault-induced degradation may threaten operational safety, transfer reliability, and maintenance efficiency. However, condition monitoring and fault diagnosis often rely on heterogeneous multi-source data, where redundant information, unequal channel sensitivity, and inter-signal coupling may obscure discriminative fault features. To address this challenge, this paper proposes a hierarchical multi-source condition monitoring and fault diagnosis framework for LNG submersible centrifugal pumps by integrating an Entropy-Weighted Sensor Selection Method (EWSSM) with a hybrid convolutional neural network (CNN)–Transformer model. Functional information is used for front-end abnormality screening, while selected response signals are used for fault category recognition. EWSSM evaluates channel contribution and suppresses redundant inputs to construct a compact fault-sensitive input space. The CNN–Transformer model combines local feature extraction with global dependency modeling to identify complex fault patterns. A laboratory-scale fault simulation platform was established, and vibration, acoustic, internal pressure-pulsation-related response information, and operating parameter data were collected under ten operating states. Experimental results show that the proposed framework achieves effective abnormality screening and accurate fault diagnosis, with an average classification accuracy of 98.73% over repeated experiments. Covariance-difference analysis further provides interpretable evidence for condition assessment by revealing fault-related multi-source response redistribution. The proposed framework provides an effective, intelligent monitoring and diagnosis solution for LNG submersible centrifugal pumps and supports reliability-oriented operation and maintenance of marine energy transportation equipment. Full article

(This article belongs to the Special Issue Dynamics and Control of Marine Mechatronics)

► Show Figures

Figure 1

19 pages, 3103 KB

Open AccessArticle

Study on the Prediction Model of Hydrate Secondary Formation Considering High-Velocity Fluid Impact

by Yunjian Zhou, Qingping Li, Yufa He and Shihui Sun

J. Mar. Sci. Eng. 2026, 14(14), 1261; https://doi.org/10.3390/jmse14141261 - 8 Jul 2026

Abstract

In the process of offshore natural gas extraction, natural gas hydrates tend to form within the wellbore. This secondary hydrate formation can potentially cause severe blockages. Current prediction methods primarily rely on temperature–pressure curves, which often overlook the critical effects of high-velocity fluid [...] Read more.

In the process of offshore natural gas extraction, natural gas hydrates tend to form within the wellbore. This secondary hydrate formation can potentially cause severe blockages. Current prediction methods primarily rely on temperature–pressure curves, which often overlook the critical effects of high-velocity fluid flow, particularly the impact and drag forces acting on the hydrates. To address this limitation, this study proposes a novel risk prediction model that innovatively decomposes the hydrate-induced wellbore blockage into three distinct stages: implantation, scour, and fracture. Each stage is mathematically evaluated using a dedicated analytical model: the impulse equation for implantation, the negative pressure suction equation for scour, and the hydrate fracture toughness equation for fracture. A region is deemed at risk of hydrate blockage only when all three stage conditions are simultaneously satisfied. Sensitivity analysis focusing on four key parameters—hydrate particle size, temperature, gas flow rate, and impact angle—revealed that increasing either the hydrate particle size during nucleation or the extraction temperature significantly reduces the risk of secondary hydrate blockage. Moreover, a typical case study demonstrated that the application of this three-stage model considerably narrows and refines the predicted risk area compared to traditional thermodynamic models. These results provide a solid theoretical foundation for accurately predicting secondary hydrate blockage risks and offer targeted strategies for flow assurance and mitigation in critical wellbore sections. Full article

(This article belongs to the Special Issue Marine Gas Hydrates: Formation, Storage, Exploration and Exploitation)

► Show Figures

Figure 1

20 pages, 1656 KB

Open AccessArticle

Short-Term Bed-Level Dynamics of an Intertidal Shoal After Large-Scale Nourishment

by Tim J. Grandjean, Jim van Belzen, Daphne van der Wal, P. Lodewijk M. de Vet, Jeroen van Dalen, Jaco C. de Smit, Zhengquan Zhou, Johan van de Koppel, Tjeerd J. Bouma and Brenda Walles

J. Mar. Sci. Eng. 2026, 14(14), 1260; https://doi.org/10.3390/jmse14141260 - 8 Jul 2026

Abstract

Erosion and habitat loss on intertidal flats are increasingly fought through large-scale sediment nourishment. Yet the impact of nourishment on short-term bed-level dynamics remains poorly quantified. Daily erosion–accretion events shape the immediate physical environment experienced by benthic infauna: repeated burial and re-exposure set [...] Read more.

Erosion and habitat loss on intertidal flats are increasingly fought through large-scale sediment nourishment. Yet the impact of nourishment on short-term bed-level dynamics remains poorly quantified. Daily erosion–accretion events shape the immediate physical environment experienced by benthic infauna: repeated burial and re-exposure set the physical bounds of the ecological niche, making bed-level dynamics a key indicator of habitat suitability that annual bathymetric surveys fail to capture. We evaluate the impact of a large-scale (1.13 million m³) nourishment at Roggenplaat in the Eastern Scheldt, Netherlands (2019) on bed-level dynamics, comparing daily bed-level changes between nourished and adjacent non-nourished areas with millimetre precision over five years. We assess three dimensions: persistence (temporal memory of the bed-level state), volatility (the frequency and magnitude of daily change), and sensitivity (the coupling between forcing and bed-level response). Two key insights emerge. First, nourished areas showed larger daily fluctuations, but event-driven bed-level changes were indistinguishable between treatments. Second, nourishment shifted the forcing balance: storm events dominate erosion in non-nourished areas, whereas in nourished areas, spring tides alone drive both accretion and erosion. Ecologically, the elevated daily disturbance is expected to act as a community-assembly filter, selecting for mobile infauna rather than excluding colonisation. These findings suggest that, although nourishment elevates day-to-day bed-level activity, its episodic disturbance regime remains compatible with the native bed-level regime, with implications for benthic habitat assessment at future restoration sites. Full article

(This article belongs to the Special Issue Linking Sedimentary and Erosive Processes with Morphodynamics in Coastal Zones)

► Show Figures

Figure 1

24 pages, 4826 KB

Open AccessArticle

Analysis of the Adaptability and Application of Matched-Field Processors for Stationary and Maneuvering Targets in Shallow Water

by Zikun Meng, Wen Zhang, Jian Shi, Shuo Liu and Qiankun Yu

J. Mar. Sci. Eng. 2026, 14(14), 1259; https://doi.org/10.3390/jmse14141259 - 8 Jul 2026

Abstract

Passive acoustic localization in complex shallow waters requires algorithms tailored to specific operational constraints. This paper investigates the adaptability, computational efficiency, and statistical performance boundaries of five matched-field processing (MFP) methods—Bartlett, Minimum Variance Distortionless Response (MVDR), Multiple Signal Classification (MUSIC), Reduced Covariance Matrix [...] Read more.

Passive acoustic localization in complex shallow waters requires algorithms tailored to specific operational constraints. This paper investigates the adaptability, computational efficiency, and statistical performance boundaries of five matched-field processing (MFP) methods—Bartlett, Minimum Variance Distortionless Response (MVDR), Multiple Signal Classification (MUSIC), Reduced Covariance Matrix (RCM), and Rank and Trace Minimization (RTM)—using the Elba-93 sea trial dataset. Error metrics and processing complexities are systematically evaluated across stationary and maneuvering target scenarios. Rigorous non-parametric statistical tests reveal distinct operational boundaries: under stationary conditions dominated by systemic environmental mismatch, energy-based processors guarantee reliable baseline stability. Conversely, under snapshot-deficient dynamic conditions tracking a receding target, standard high-resolution subspace methods become highly vulnerable to trajectory jumps. In such highly dynamic scenarios, adaptive energy-based processors (specifically MVDR) exhibit the most stable tracking continuity and lowest numerical peak errors. Simultaneously, the operational adaptability of subspace methods is improved via covariance matrix reconstruction (CMR). Specifically, the RCM technique effectively decouples unstructured sensor noise, mitigating maximum trajectory deviations and providing a balanced trade-off between computational efficiency and robustness. Statistical evaluations confirm the fundamental performance boundaries in static environments, while highlighting sample-size limitations in highly dynamic scenarios, thereby establishing a realistic, evidence-based benchmark for marine engineering applications. Full article

(This article belongs to the Topic Advances in Underwater Signal Processing and Communication: Challenges, Innovations, and Applications)

► Show Figures

Figure 1

31 pages, 2402 KB

Open AccessReview

AIS Cybersecurity: Challenges, Vulnerabilities, and Mitigation Strategies

by Silvie Levy, Ehud Gudess and Danny Hendler

J. Mar. Sci. Eng. 2026, 14(14), 1258; https://doi.org/10.3390/jmse14141258 - 8 Jul 2026

Abstract

Maritime operations rely on the Automatic Identification System (AIS), an open broadcast protocol whose unauthenticated, self-reported messages are easily abused. This survey provides an AIS-first, security-focused synthesis of AIS cybersecurity research. It makes three main contributions. First, it explains AIS protocol mechanics and [...] Read more.

Maritime operations rely on the Automatic Identification System (AIS), an open broadcast protocol whose unauthenticated, self-reported messages are easily abused. This survey provides an AIS-first, security-focused synthesis of AIS cybersecurity research. It makes three main contributions. First, it explains AIS protocol mechanics and uses them to derive the main security weaknesses that arise from open VHF broadcast, self-reported data, lack of built-in authentication and replay protection, and GNSS dependence. Second, it organizes AIS threats and mitigations into a unified taxonomy that links attack vectors, technical effects, operational impacts, and security measures across the prevent–detect–respond–recover lifecycle. Third, it assesses practical defenses, including authentication proposals, endpoint and network hardening, behavior-aware analytics, cross-sensor validation, and governance measures. The survey shows that existing work is strongest on anomaly detection and AIS data analytics, whereas standards-compatible authentication, scalable key management, backward-compatible deployment, trust-aware display integration, and operational validation remain open challenges. Consequently, AIS security is likely to require layered, staged, and standards-compatible mitigations rather than a single technical fix. By bringing together cybersecurity, maritime operations, and data-science perspectives, the survey provides practical guidance for securing AIS-based systems and highlights open problems for future standardization and implementation. Full article

(This article belongs to the Special Issue Maritime Transportation Safety and Risk Management)

► Show Figures

Figure 1

36 pages, 2900 KB

Open AccessArticle

Experimental Study on Hydrodynamic Characteristics of a Disk-Shaped Buoy Using a Large-Scale Wave Flume

by Zhonghua Tan, Hanbao Chen, Songgui Chen, Ning Guan, Yingni Luan, Wenjun Shen and Jiming Zhang

J. Mar. Sci. Eng. 2026, 14(14), 1257; https://doi.org/10.3390/jmse14141257 - 8 Jul 2026

Abstract

This study presents (i) a hybrid experimental strategy combining a large-scale wave flume and harbor basin for broad-period buoy hydrodynamic characterization, with internal consistency assessment across the facility transition, (ii) a comprehensive, uncertainty-quantified dataset for a shallow-draft disk-shaped buoy (D/T ≈ 10) including [...] Read more.

This study presents (i) a hybrid experimental strategy combining a large-scale wave flume and harbor basin for broad-period buoy hydrodynamic characterization, with internal consistency assessment across the facility transition, (ii) a comprehensive, uncertainty-quantified dataset for a shallow-draft disk-shaped buoy (D/T ≈ 10) including RAOs with repeatability statistics, extreme sea-state responses, and environmental load coefficients with uncertainty bounds, and (iii) new physical insights into the roll damping mechanism of such geometries without appendages. A hybrid experimental strategy was employed, integrating a large-scale wave flume (for long-period waves and currents) with a harbor basin (for short-period waves and wind), aiming to mitigate the scale effects inherent in Froude-scaled models, particularly with regard to drag force measurements. The test matrix included free decay in calm water, RAOs under regular waves, motion and mooring line tension under irregular waves, and measurements of wind and current drag coefficients. Key results indicate a natural roll period of approximately 3.0 s (prototype) with a notably high dimensionless damping ratio (ζ ≈ 0.14–0.15), which is conducive to rapid motion attenuation. A pronounced resonance peak in the roll RAO (26.6°/m) was observed near the 3.0 s. Under an extreme sea state (prototype: H_s = 13.8 m, T_p = 16.1 s), the maximum roll angle and dynamic mooring line tension reached 21.30° and 61.56 kN, respectively, the latter being about 3.0 times the static pretension. The mean wind drag coefficient and current drag coefficient were determined as 0.76 and 0.44. This research provides a comprehensive dataset with quantified uncertainty and critical insights for the design, mooring system optimization, and operational safety assessment of such disk-shaped buoys. The hybrid testing approach demonstrated qualitative consistency across the two facilities, pending quantitative cross-validation through dedicated overlapping tests, and the measured roll damping (ζ = 0.14–0.15, expanded uncertainty ±0.01–0.011) is favorable for motion stability within the tested Reynolds-number range. Full-scale validation is recommended to confirm these findings under prototype conditions. Wind, wave, and current effects were tested separately and then comprehensively assessed. Full article

(This article belongs to the Special Issue Wave Loads on Offshore Structure—2nd Edition)

► Show Figures

Figure 1

Journal Description

Journal of Marine Science and Engineering

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Further Information

Guidelines

MDPI Initiatives

Follow MDPI