Journal of Marine Science and Engineering

16 pages, 2242 KB

Open AccessArticle

Hydraulic Design Optimization of a Multi-Stage Overtopping Wave Energy Converter Using WCSPH Methodology Under Site-Specific Wave Conditions

by Sung-Hwan An and Jong-Hyun Lee

J. Mar. Sci. Eng. 2026, 14(2), 127; https://doi.org/10.3390/jmse14020127 - 7 Jan 2026

Abstract

In multi-level overtopping wave energy converters (OWEC), the inlet slot governs overtopping losses and the distribution of inflow among reservoirs, making it a critical design feature for maximizing hydraulic efficiency. This study defines the relative slot width as

λ

(=w/ [...] Read more.

In multi-level overtopping wave energy converters (OWEC), the inlet slot governs overtopping losses and the distribution of inflow among reservoirs, making it a critical design feature for maximizing hydraulic efficiency. This study defines the relative slot width as

λ

(=w/

L_{s l o p}

) and investigates its influence on the performance of an SSG-based multi-level OWEC using DualSPHysics, an open-source weakly compressible smoothed particle hydrodynamics (WCSPH) solver, in a two-dimensional recirculating numerical wave tank under regular-wave conditions. Hydraulic efficiency is evaluated as the ratio of the overtopping-stored potential-energy flux to the incident wave energy flux per unit width. The results show a nonlinear dependence of reservoir-level contributions on

λ

, and an intermediate

λ

provides a balanced contribution across upper, middle, and lower reservoirs, yielding the maximum overall efficiency. To extend the analysis beyond a single design wave, a global-state performance map in the period–height space is constructed and combined with the target-sea spectral characteristics, indicating that the optimal geometry maintains relatively robust efficiency in the dominant spectral band while revealing efficiency limitations associated with insufficient overtopping at small waves and saturation at large waves. The proposed approach provides quantitative guidance for slot design and site-relevant performance screening of multi-level OWEC. Full article

(This article belongs to the Special Issue Challenges of Marine Energy Development and Facilities Engineering)

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17 pages, 2618 KB

Open AccessArticle

Experimental Study on Mechanism of Using Complex Nanofluid Dispersions to Enhance Oil Recovery in Tight Offshore Reservoirs

by Zhisheng Xing, Xingyuan Liang, Guoqing Han, Fujian Zhou, Kai Yang and Shuping Chang

J. Mar. Sci. Eng. 2026, 14(2), 126; https://doi.org/10.3390/jmse14020126 - 7 Jan 2026

Abstract

Horizontal wells combined with multi-stage fracturing are key techniques for extracting tight oil formation. However, due to the ultra-low permeability and porosity of reservoirs, energy depletion occurs rapidly, necessitating external supplements to sustain production. During the hydraulic fracturing process, large volumes of fracturing [...] Read more.

Horizontal wells combined with multi-stage fracturing are key techniques for extracting tight oil formation. However, due to the ultra-low permeability and porosity of reservoirs, energy depletion occurs rapidly, necessitating external supplements to sustain production. During the hydraulic fracturing process, large volumes of fracturing fluid are injected into reservoirs, increasing its pressure to a certain extent. However, due to the oil-wet nature of the formation, the fracturing fluid cannot penetrate the rock, failing to enhance oil recovery during the shut-in period. Surfactant-based nanofluids have been introduced as fracturing fluid additives to reverse rock wettability, thereby boosting imbibition-driven recovery. Although the imbibition has been studied to inspire the tight oil recovery, few studies have demonstrated the imbibition in enhanced fossil hydrogen energy, which further promotes the imbibition recovery. In this paper, complex nanofluid dispersions (CND) have been proved to enhance the tight reservoir pressure. Through contact angle and imbibition experiments, it is shown that CND can transform oil-wet rock to water-wet, reduce the adhesion of oil, and improve the ultimate oil recovery through the imbibition effect. Then, core flow testing experiments were conducted to show CND can decrease the flow resistance and improve the swept area of the injected fluid. In the end, pressure transmission tests were conducted to show CND can enhance the formation energy and production after fracturing. Results demonstrate that CND enables the fracturing fluid to travel further away from the hydraulic fractures, thus decreasing the depletion of tight formation pressure and maintaining a higher oil production rate. Results help optimize the design of the hydraulic fracturing of tight offshore reservoirs. Full article

(This article belongs to the Special Issue Advances in Offshore Oil and Gas Exploration and Development)

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17 pages, 4574 KB

Open AccessArticle

Linking Sidescan Sonar Backscatter Intensity to Seafloor Sediment Grain Size Fractions: Insight from Dongluo Island

by Songyang Ma, Bin Li, Peng Wan, Chengfu Wei, Zhijian Chen, Ruikeng Li, Zhenqiang Zhao, Chi Chen, Jiangping Yang, Jun Tu and Mingming Wen

J. Mar. Sci. Eng. 2026, 14(2), 125; https://doi.org/10.3390/jmse14020125 - 7 Jan 2026

Abstract

Accurate characterization of seafloor sediment properties is critical for marine engineering design, resource assessment, and environmental management. Sidescan sonar offers efficient wide-area mapping capabilities, yet establishing robust quantitative relationships between acoustic backscatter intensity and sediment texture remains challenging, particularly in heterogeneous coastal environments. [...] Read more.

Accurate characterization of seafloor sediment properties is critical for marine engineering design, resource assessment, and environmental management. Sidescan sonar offers efficient wide-area mapping capabilities, yet establishing robust quantitative relationships between acoustic backscatter intensity and sediment texture remains challenging, particularly in heterogeneous coastal environments. This study investigates the correlation between sidescan sonar backscatter intensity and sediment grain size parameters in waters southwest of Hainan Island, China. High-resolution acoustic data (450 kHz) were acquired alongside surface sediment samples from 18 stations spanning diverse sediment types. Backscatter intensity, represented by grayscale values, was systematically compared with grain size distributions and individual size fractions. Results reveal that mean grain size shows no meaningful correlation with backscatter intensity; however, fine sand fraction content (0.075–0.25 mm) exhibits a strong negative linear relationship (R² = 0.87 under optimal conditions). Distribution-level analysis demonstrates that backscatter variability mirrors sediment textural complexity, with coarse sediments producing broad, elevated intensity distributions and fine sediments yielding narrow, suppressed distributions. Inter-survey variability highlights the sensitivity of absolute intensity values to environmental conditions during acquisition. Spatial distribution analysis reveals that sediment grain size follows a systematic NE-SW gradient controlled by hydrodynamic energy, with notable local anomalies controlled by reef structures (producing coarse bioclastic sediment) and topographic sheltering (maintaining fine-grained deposits in shallow areas). These findings provide a quantitative basis for fraction-specific acoustic classification approaches while emphasizing the importance of multi-scale analysis incorporating both regional hydrodynamic trends and local morphological controls. The established relationship between fine sand abundance and acoustic response enables semi-quantitative sediment prediction from remotely sensed data, supporting improved seafloor mapping protocols for offshore infrastructure siting, aggregate resource evaluation, and coastal zone management in morphologically complex environments. Full article

(This article belongs to the Section Geological Oceanography)

26 pages, 6272 KB

Open AccessArticle

Target Detection in Ship Remote Sensing Images Considering Cloud and Fog Occlusion

by Xiaopeng Shao, Zirui Wang, Yang Yang, Shaojie Zheng and Jianwu Mu

J. Mar. Sci. Eng. 2026, 14(2), 124; https://doi.org/10.3390/jmse14020124 - 7 Jan 2026

Abstract

The recognition of targets in ship remote sensing images is crucial for ship collision avoidance, military reconnaissance, and emergency rescue. However, climatic factors such as clouds and fog can obscure and blur remote sensing image targets, leading to missed and false detections in [...] Read more.

The recognition of targets in ship remote sensing images is crucial for ship collision avoidance, military reconnaissance, and emergency rescue. However, climatic factors such as clouds and fog can obscure and blur remote sensing image targets, leading to missed and false detections in target detection. Therefore, it is necessary to study ship remote sensing target detection that considers the impact of cloud and fog occlusion. Due to the large scale and vast amount of information in remote sensing images, in order to achieve high-precision target detection based on limited resource platforms, a comparison of the detection accuracy and parameter quantity of the YOLO series algorithms was first conducted. Based on the analysis results, the YOLOv8s network model with the least number of parameters while ensuring detection accuracy was selected for lightweight network model improvement. The FasterNet was utilized to replace the backbone feature extraction network of YOLOv8s, and the detection accuracy and lightweight level of the resulting FN-YOLOv8s network model were both improved. Furthermore, structural improvements were made to the AOD-Net dehazing network. By introducing a smoothness loss function, the halo artifacts often generated during the image dehazing process were addressed. Meanwhile, by integrating the atmospheric light value and transmittance, the accumulation error was effectively reduced, significantly enhancing the dehazing effect of remote sensing images. Full article

(This article belongs to the Section Ocean Engineering)

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25 pages, 3863 KB

Open AccessArticle

Tidal Dynamics Shaped the Dissolved Organic Carbon Fate and Exchange Flux Across Estuary-Coastal Water Continuum in Zhanjiang Bay, China

by Xiao-Ling Chen, Peng Zhang, Ying-Xian He, Lin Zhou and Ji-Biao Zhang

J. Mar. Sci. Eng. 2026, 14(2), 123; https://doi.org/10.3390/jmse14020123 - 7 Jan 2026

Abstract

Dissolved organic matter (DOM) is central to biogeochemical cycles in estuarine-coastal zones, with its source-sink dynamics linking regional ecological functions to global carbon budgets. As a typical semi-enclosed bay in southern China, Zhanjiang Bay (ZJB) features intense tidal mixing and significant seasonal runoff [...] Read more.

Dissolved organic matter (DOM) is central to biogeochemical cycles in estuarine-coastal zones, with its source-sink dynamics linking regional ecological functions to global carbon budgets. As a typical semi-enclosed bay in southern China, Zhanjiang Bay (ZJB) features intense tidal mixing and significant seasonal runoff variations, making it a representative system for understanding DOM dynamics in complex land–sea interaction zones. The migration of dissolved organic carbon (DOC) is crucial for bay carbon budgets, yet its estimation is constrained by land–water interface dynamics and in situ observation limitations. To clarify the regulation of DOM’s fate and exchange flux in ZJB, this study integrated in situ observations, ultraviolet spectroscopy, and three-dimensional fluorescence techniques to analyze DOM tidal dynamics and net DOC exchange flux. Results indicated terrestrial runoff dominated rainy-season DOC sources, resulting in slightly higher concentrations (1.86 ± 0.46 mg·L⁻¹) compared to the dry season (1.82 ± 0.20 mg·L⁻¹). Terrestrial inputs endowed rainy-season DOM with high molecular weight and aromaticity, with microbial humic substances (C2) accounting for 36%. Tidal fluctuations affected DOC via water exchange: ebb tides diluted concentrations with low-DOC open-ocean seawater, while flood tides increased them through high-DOC bay water discharge. Dry-season DOM relied on in situ biotransformation, characterized by low molecular weight and aromaticity, with the protein-like fraction (C4) accounting for 24.2%. Fluorescence index (FI = 1.77–1.79) confirmed DOM as a mixture of allochthonous and autochthonous sources, with significant in situ contributions and weak humification. Net DOC exchange flux, regulated by terrestrial runoff, was 3.6–4.6 times higher in the rainy season, decreasing from the estuary to the coast. In conclusion, the joint regulation of terrestrial runoff-driven seasonal dynamics and tidal water exchange governs ZJB’s DOM dynamics, providing valuable insights for biogeochemical research in semi-enclosed bays. Full article

(This article belongs to the Special Issue Selected Feature Papers in Marine Environmental Science)

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21 pages, 1550 KB

Open AccessArticle

Analytical Evaluation of Hull-Design Parameters Affecting Ship Controllability and Dynamic Behaviour with Integrated Electric–Propulsion Systems

by Volodymyr Yarovenko, Oleksandr Shumylo, Mykola Malaksiano, Oleksiy Melnyk, Pavlo Nosov, Václav Píštěk and Pavel Kučera

J. Mar. Sci. Eng. 2026, 14(2), 122; https://doi.org/10.3390/jmse14020122 - 7 Jan 2026

Abstract

This study presents an analytical methodology for evaluating the influence of hull design parameters on the controllability and manoeuvrability of ships equipped with integrated electric propulsion systems. Unlike traditional approaches that examine the hull and propulsion plant independently, the proposed method employs a [...] Read more.

This study presents an analytical methodology for evaluating the influence of hull design parameters on the controllability and manoeuvrability of ships equipped with integrated electric propulsion systems. Unlike traditional approaches that examine the hull and propulsion plant independently, the proposed method employs a generalized model of transient modes within the propulsion complex, enabling the coupled interaction among the hull, propulsion units, electric motors, and the electrical power system to be captured during manoeuvring. Active experimental design and regression modelling are applied to construct controllability diagrams, identify the most influential dimensionless parameters, and reduce computational effort. The methodology is used to assess the effect of hull elongation (0.08–0.16 L) with curvature variation limited to 6%. The results show that this degree of elongation has minimal impact on turning performance and course-keeping stability, confirming the feasibility of such design modifications. The proposed approach provides an effective tool for early-stage design and modernization of electric ships and supports decision-making in ship behaviour prediction and traffic management. Full article

(This article belongs to the Special Issue Management and Control of Ship Traffic Behaviours)

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20 pages, 4893 KB

Open AccessArticle

Motion Analysis of a Fully Wind-Powered Ship by Using CFD

by Akane Yasuda, Tomoki Taniguchi and Toru Katayama

J. Mar. Sci. Eng. 2026, 14(2), 121; https://doi.org/10.3390/jmse14020121 - 7 Jan 2026

Abstract

This study investigates the sailing performance and maneuverability of a fully wind-powered ship equipped with two rigid wing sails and a rudder, using Computational Fluid Dynamics (CFD). Unlike some conventional approaches that separately analyze above-water and underwater forces, this research employs a comprehensive [...] Read more.

This study investigates the sailing performance and maneuverability of a fully wind-powered ship equipped with two rigid wing sails and a rudder, using Computational Fluid Dynamics (CFD). Unlike some conventional approaches that separately analyze above-water and underwater forces, this research employs a comprehensive CFD model to predict ship motion and performance under various wind directions and sail angles, from a stationary state to steady sailing. The accuracy of the CFD method is confirmed through comparison with experimental drift test data. Although the simulated drift data showed some discrepancies from the observed data due to the difficulty of accurately modeling the wind field in the simulation, the results indicate that the CFD method can effectively reproduce the ship motions observed in the experiments. Simulations reveal that the previously proposed L-shaped and T-shaped sail arrangements, which were designed to maximize thrust without considering maneuvering effects, remain effective even when ship motion is included. However, the results also show that conventional sail arrangements can achieve higher steady-state speeds due to reduced leeway-related resistance, while the L-shaped and T-shaped arrangements yield distinct steady-state leeway (drift) characteristics under heading control. These findings suggest that dynamically adjusting sail arrangements according to operational requirements may help manage the ship’s trajectory (lateral offset) and mitigate maneuvering difficulties, contributing to the practical application of fully wind-powered ships. The study provides quantitative insights into the relationship between sail arrangement, acceleration, and leeway/drift behavior, supporting the design of next-generation wind-powered ships. Full article

(This article belongs to the Section Ocean Engineering)

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20 pages, 3462 KB

Open AccessArticle

Sea Surface Temperature Prediction Based on Adaptive Coordinate-Attention Transformer

by Naihua Ji, Yue Dai, Menglei Xia, Shuai Guo, Tianhui Qiu and Lu Yu

J. Mar. Sci. Eng. 2026, 14(2), 120; https://doi.org/10.3390/jmse14020120 - 7 Jan 2026

Abstract

Sea surface temperature (SST) serves as a critical indicator of oceanic thermodynamic processes and climate variability, exerting essential influence on ocean fronts, typhoon tracks, and monsoon evolution. Nevertheless, owing to the highly nonlinear and complex multi-scale characteristics of SST, achieving accurate spatiotemporal forecasting [...] Read more.

Sea surface temperature (SST) serves as a critical indicator of oceanic thermodynamic processes and climate variability, exerting essential influence on ocean fronts, typhoon tracks, and monsoon evolution. Nevertheless, owing to the highly nonlinear and complex multi-scale characteristics of SST, achieving accurate spatiotemporal forecasting remains a formidable challenge. To address this issue, we proposed an enhanced Transformer architecture that incorporates a Coordinate Attention (CA) module and an Adaptive Fusion (AD) module, enabling the joint extraction and integration of temporal and spatial features. The proposed model is evaluated through SST prediction experiments over a localized region of the South China Sea with lead times of 1, 7, 15, and 30 days. Results indicate that our approach consistently outperforms baseline models across multiple evaluation metrics. Moreover, generalization experiments conducted on datasets from regions with diverse latitudes and climate regimes further demonstrate the model’s robustness and adaptability in terms of both accuracy and stability. Full article

(This article belongs to the Section Physical Oceanography)

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21 pages, 3483 KB

Open AccessArticle

Morphological and Mechanical Characterization of the Limpet Shells from the Korean Intertidal Coast

by Ji Yeong Kim, Baek-Jun Kim, Yeweon Jin and Eung-Sam Kim

J. Mar. Sci. Eng. 2026, 14(2), 119; https://doi.org/10.3390/jmse14020119 - 7 Jan 2026

Abstract

This study was conducted to elucidate how shell form contributes to functional adaptation and mechanical optimization in seven limpet species inhabiting intertidal zones along the Korean coast. Ten morphological and weight-related parameters were measured, revealing clear interspecific differences in shell form and mass-related [...] Read more.

This study was conducted to elucidate how shell form contributes to functional adaptation and mechanical optimization in seven limpet species inhabiting intertidal zones along the Korean coast. Ten morphological and weight-related parameters were measured, revealing clear interspecific differences in shell form and mass-related traits. Multivariate shape analysis indicated that shell morphology varied primarily with overall size, with additional variation associated with apex position and height-to-length proportions. Compressive strength tests showed that shell thickness (ST), shell height (SH), and elliptical area (EA) were key determinants of mechanical resistance, with dome-shaped species exhibiting greater load-bearing capacity than flatter forms. Integrating geometric and mechanical data indicated that shell robustness arises from coordinated structural proportions rather than any single dimension. Overall, the results provide an integrated understanding of how morphological design and mechanical performance together shape the ecological and evolutionary strategies of limpets in dynamic intertidal environments. Full article

(This article belongs to the Special Issue Feature Papers in Marine Biology, 2nd Edition)

27 pages, 1856 KB

Open AccessArticle

Waypoint-Sequencing Model Predictive Control for Ship Weather Routing Under Forecast Uncertainty

by Marijana Marjanović, Jasna Prpić-Oršić and Marko Valčić

J. Mar. Sci. Eng. 2026, 14(2), 118; https://doi.org/10.3390/jmse14020118 - 7 Jan 2026

Abstract

Ship weather routing optimization has evolved from deterministic great-circle navigation to sophisticated frameworks that account for dynamic environmental conditions and operational constraints. This paper presents a waypoint-sequencing Model Predictive Control (MPC) approach for energy-efficient ship weather routing under forecast uncertainty. The proposed rolling [...] Read more.

Ship weather routing optimization has evolved from deterministic great-circle navigation to sophisticated frameworks that account for dynamic environmental conditions and operational constraints. This paper presents a waypoint-sequencing Model Predictive Control (MPC) approach for energy-efficient ship weather routing under forecast uncertainty. The proposed rolling horizon framework integrates neural network-based vessel performance models with ensemble weather forecasts to enable real-time route adaptation while balancing fuel efficiency, navigational safety, and path smoothness objectives. The MPC controller operates with a 6 h control horizon and 24 h prediction horizon, re-optimizing every 6 h using updated meteorological forecasts. A multi-objective cost function prioritizes fuel consumption (60%), safety considerations (30%), and trajectory smoothness (10%), with an exponential discount factor (γ = 0.95) to account for increasing forecast uncertainty. The framework discretises planned routes into waypoints and optimizes heading angles and discrete speed options (12.0, 13.5, and 14.5 knots) at each control step. Validation using 21 transatlantic voyage scenarios with real hindcast weather data demonstrates the method’s capability to propagate uncertainties through ship performance models, yielding probabilistic estimates for attainable speed, fuel consumption, and estimated time of arrival (ETA). The methodology establishes a foundation for more advanced stochastic optimization approaches while offering immediate operational value through its computational tractability and integration with existing ship decision support systems. Full article

(This article belongs to the Special Issue The Control and Navigation of Autonomous Surface Vehicles)

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28 pages, 3587 KB

Open AccessArticle

Coupled Responses and Performance Assessment of Mooring-Connection Systems for Floating Photovoltaic Arrays in Shallow Waters

by Xiao Wang, Shuqing Wang, Xiancang Song and Bingtao Song

J. Mar. Sci. Eng. 2026, 14(2), 117; https://doi.org/10.3390/jmse14020117 - 7 Jan 2026

Abstract

Offshore floating photovoltaic (FPV) platforms are usually deployed in shallow waters with large tidal variations, where the modules of FPV are connected with each other via the connectors to form an array and mounted to the seabed via the mooring system. Therefore, the [...] Read more.

Offshore floating photovoltaic (FPV) platforms are usually deployed in shallow waters with large tidal variations, where the modules of FPV are connected with each other via the connectors to form an array and mounted to the seabed via the mooring system. Therefore, the mooring system and module connectors have significant influence on the dynamic response characteristics of FPV. In targeting such shallow waters with large tidal ranges, this paper proposes four integrated mooring-connection schemes based on configuration and parameter customization guided by adaptability optimization, including two kinds of mooring systems, named as horizontal mooring system and catenary mooring system with clumps, and two kinds of connection schemes, named as cross-cable connection and hybrid connection, are proposed. The feasibility of the mooring systems to adhere to the tidal range and the influence of the connection schemes on the dynamic response of the FPV are numerically investigated in detail. Results indicate the two mooring systems have comparable positioning performance; horizontal mooring offers slightly better tidal adaptability but much higher mooring tension, compromising system safety. Hybrid connection yields smaller surge amplitudes than cross-cable connection but generates excessively large connection forces, also posing safety risks. Comprehensive comparison indicates that catenary mooring with clumps combined with cross-cable connection imposes lower requirements on platform structural safety factors, while horizontal mooring with cross-cable connection exhibits stronger adaptability to water level and environmental load direction changes in shallow waters. Full article

(This article belongs to the Special Issue Advanced Analysis of Ship and Offshore Structures)

23 pages, 5241 KB

Open AccessArticle

BAARTR: Boundary-Aware Adaptive Regression for Kinematically Consistent Vessel Trajectory Reconstruction from Sparse AIS

by Hee-jong Choi, Joo-sung Kim and Dae-han Lee

J. Mar. Sci. Eng. 2026, 14(2), 116; https://doi.org/10.3390/jmse14020116 - 7 Jan 2026

Abstract

The Automatic Identification System (AIS) frequently suffers from data loss and irregular report intervals in real maritime environments, compromising the reliability of downstream navigation, monitoring, and trajectory reconstruction tasks. To address these challenges, we propose BAARTR (Boundary-Aware Adaptive Regression for Kinematically Consistent Vessel [...] Read more.

The Automatic Identification System (AIS) frequently suffers from data loss and irregular report intervals in real maritime environments, compromising the reliability of downstream navigation, monitoring, and trajectory reconstruction tasks. To address these challenges, we propose BAARTR (Boundary-Aware Adaptive Regression for Kinematically Consistent Vessel Trajectory Reconstruction), a novel kinematically consistent interpolation framework. Operating solely on time, latitude, and longitude inputs, BAARTR explicitly enforces boundary velocities derived from raw AIS data. The framework adaptively selects a velocity-estimation strategy based on the AIS reporting gap: central differencing is applied for short intervals, while a hierarchical cubic velocity regression with a quadratic acceleration constraint is employed for long or irregular gaps to iteratively refine endpoint slopes. These boundary slopes are subsequently incorporated into a clamped quartic interpolation at a 1 s resolution, effectively suppressing overshoots and ensuring velocity continuity across segments. We evaluated BAARTR against Linear, Spline, Hermite, Bezier, Piecewise cubic hermite interpolating polynomial (PCHIP) and Modified akima (Makima) methods using real-world AIS data collected from the Mokpo Port channel, Republic of Korea (2023–2024), across three representative vessels. The experimental results demonstrate that BAARTR achieves superior reconstruction accuracy while maintaining strictly linear time complexity (

O (N)

). BAARTR consistently achieved the lowest median Root Mean Square Error (RMSE) and the narrowest Interquartile Ranges (IQR), producing visibly smoother and more kinematically plausible paths-especially in high-curvature turns where standard geometric interpolations tend to oscillate. Furthermore, sensitivity analysis shows stable performance with a modest training window (n ≈ 16) and minimal regression iterations (m = 2–3). By reducing reliance on large training datasets, BAARTR offers a lightweight, extensible foundation for post-processing in Maritime Autonomous Surface Ship (MASS) and Vessel Traffic Service (VTS), as well as for accident reconstruction and multi-sensor fusion. Full article

(This article belongs to the Special Issue Advanced Research on Path Planning for Intelligent Ships)

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20 pages, 8043 KB

Open AccessArticle

Development of a Cost-Effective UUV Localisation System Integrable with Aquaculture Infrastructure

by Thein Than Tun, Loulin Huang and Mark Anthony Preece

J. Mar. Sci. Eng. 2026, 14(2), 115; https://doi.org/10.3390/jmse14020115 - 7 Jan 2026

Abstract

In many aquaculture farms, Unmanned Underwater Vehicles (UUVs) are being deployed to perform dangerous and time-consuming repetitive tasks (e.g., fish net-pen visual inspection) on behalf of or in collaboration with farm operators. Mostly, they are remotely operated, and one of the main barriers [...] Read more.

In many aquaculture farms, Unmanned Underwater Vehicles (UUVs) are being deployed to perform dangerous and time-consuming repetitive tasks (e.g., fish net-pen visual inspection) on behalf of or in collaboration with farm operators. Mostly, they are remotely operated, and one of the main barriers to deploying them autonomously is the UUV localisation. Specifically, the cost of the localisation sensor suite, sensor reliability in constrained operational workspace and return on investment (ROI) for the huge initial investment on the UUV and its localisation hinder the R&D work and adoption of the autonomous UUV deployment on an industrial scale. The proposed system, which leverages the AprilTag (a fiducial marker used as a frame of reference) detection, provides cost-effective UUV localisation for the initial trials of autonomous UUV deployment, requiring only minor modifications to the aquaculture infrastructure. With such a cost-effective approach, UUV R&D engineers can demonstrate and validate the advantages and challenges of autonomous UUV deployment to farm operators, policymakers, and governing authorities to make informed decision-making for the future large-scale adoption of autonomous UUVs in aquaculture. Initial validation of the proposed cost-effective localisation system indicates that centimetre-level accuracy can be achieved with a single monocular camera and only 10 AprilTags, without requiring physical measurements, in a

115.46

m³ laboratory workspace under various lighting conditions. Full article

(This article belongs to the Special Issue Infrastructure for Offshore Aquaculture Farms)

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39 pages, 18338 KB

Open AccessArticle

Damage Characterisation of Scour in Riprap-Protected Jackets and Hybrid Foundations

by João Chambel, Tiago Fazeres-Ferradosa, Mahdi Alemi, Francisco Taveira-Pinto and Pedro Lomonaco

J. Mar. Sci. Eng. 2026, 14(2), 114; https://doi.org/10.3390/jmse14020114 - 6 Jan 2026

Abstract

The global transition towards sustainable energy has accelerated the development and deployment of offshore wind turbines. Jacket foundations, commonly installed in intermediate to deep water depths to access available space and higher load capacities, are built to withstand intensified hydrodynamic loads. Due to [...] Read more.

The global transition towards sustainable energy has accelerated the development and deployment of offshore wind turbines. Jacket foundations, commonly installed in intermediate to deep water depths to access available space and higher load capacities, are built to withstand intensified hydrodynamic loads. Due to their structural complexity near the seabed, however, they are prone to local and global scour, which can compromise stability and increase maintenance costs. While extensive research has addressed scour protections around monopiles, limited attention has been given to complex foundation geometries or even hybrid configurations that combine energy-harvesting devices with structural support. These hybrid systems introduce highly unsteady flow fields and amplified turbulence effects that current design frameworks appear to be unable to capture. This study provides an experimental characterisation of scour damage in riprap-protected jackets as well as additional tests for a hybrid jacket foundation. A novel adaptation of a high-resolution overlapping sub-area methodology was employed. For the first time, it was successfully applied to quantify the damage to riprap protections for a complex offshore foundation. Results revealed that, although hybrid jackets showed the capacity to attenuate incident waves, the scour protection experienced damage numbers (S_3D) two to six times higher than conventional jackets due to flow amplifications. The findings highlight the need for revised design guidelines that can account for the complex hydrodynamic-structural interactions of next-generation marine harvesting technologies integrated into complex foundations. Full article

(This article belongs to the Topic Advancements and Challenges in Marine Renewable Energy and Marine Structures)

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25 pages, 8314 KB

Open AccessArticle

Performance of Oil Spill Identification in Multiple Scenarios Using Quad-, Compact-, and Dual-Polarization Modes

by Guannan Li, Gaohuan Lv, Bingnan Li, Xiang Wang and Fen Zhao

J. Mar. Sci. Eng. 2026, 14(2), 113; https://doi.org/10.3390/jmse14020113 - 6 Jan 2026

Abstract

Oil spills, whether in open water or near shorelines, cause serious environmental problems. Moreover, polarimetric synthetic-aperture radar provides abundant oil spill information with all-weather, day–night detection capability, but its use is limited by data usage and processing costs. Compact Polarimetric (CP) systems as [...] Read more.

Oil spills, whether in open water or near shorelines, cause serious environmental problems. Moreover, polarimetric synthetic-aperture radar provides abundant oil spill information with all-weather, day–night detection capability, but its use is limited by data usage and processing costs. Compact Polarimetric (CP) systems as a subsequent emerging system, which balance data volume and system design requirements, are promising in this regard. Herein, we utilize multisource oil spill scenarios and datasets from multiple polarimetric modes (VV-HH, π/4, DCP, and CTLR) to assess the oil spill detection capability of each mode under varying incidence angles conditions, spill causes, and oil types. Using qualitative and quantitative evaluation indicators, we compare the typical features of the multiple polarization modes as well as assess their consistency with Full Polarization (FP) information and their oil spill recognition performance across different incidence angles. In large-incidence-angle oil spill scenarios, the VV–HH mode exhibits the highest information consistency with the FP mode and the strongest oil spill recognition ability. At small incidence angles, the CP mode (i.e., CTLR mode) exhibits the best overall performance, benefiting from its effective self-calibration capability and low noise sensitivity. Furthermore, despite containing comprehensive information, the FP mode is not always superior to the dual-polarization and CP modes. Thus, in oil spill scenarios across different incidence angles, incorporating features from an appropriate polarization mode into oil spill information extraction and recognition can optimize the associated efficiency. Full article

(This article belongs to the Section Marine Pollution)

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19 pages, 7474 KB

Open AccessArticle

Sedimentary–Tectonic Evolution and Paleogeographic Characteristics of the Paleozoic in the Ordos Basin

by Yuxia Wang, Junfeng Ren, Heng Wang, Jing Luo, Lifa Zhou and Jiayi Wei

J. Mar. Sci. Eng. 2026, 14(2), 112; https://doi.org/10.3390/jmse14020112 - 6 Jan 2026

Abstract

As a tectonically stable and extensively superimposed basin situated in the North China Craton, the Ordos Basin hosts abundant reserves of oil, natural gas, and coal within its Paleozoic strata, rendering it a focal area in energy-related geological research. The basin’s evolutionary history [...] Read more.

As a tectonically stable and extensively superimposed basin situated in the North China Craton, the Ordos Basin hosts abundant reserves of oil, natural gas, and coal within its Paleozoic strata, rendering it a focal area in energy-related geological research. The basin’s evolutionary history provides a comprehensive record of key geological transitions—from an Early Paleozoic carbonate platform to Late Paleozoic marine–continental transitional deposits and ultimately to continental clastic sedimentation—largely governed by the regional tectonic dynamics associated with the North China Plate. This study presents a systematic review of the sedimentary and tectonic evolution of the Paleozoic sequence in the basin. Findings indicate that during the Early Paleozoic, the basin developed under a passive continental margin setting, characterized by widespread epicontinental marine carbonate deposition. By the Late Ordovician, subduction of the Qinqi Ocean triggered the Caledonian orogeny, resulting in regional uplift across the basin, widespread erosion, and a significant hiatus in Middle to Late Ordovician sedimentation, which facilitated the formation of paleo-weathered crust karst reservoirs. In the Late Paleozoic, the basin evolved into an intracratonic depression. From the Late Carboniferous to the Early Permian, the Hercynian tectonic event influenced the transformation from isolated rift basins to a broad epicontinental sea, leading to the deposition of critical coal-bearing strata within marine–continental transitional facies. Starting in the Middle Permian, the closure of surrounding oceanic domains induced widespread tectonic uplift, shifting the depositional environment to a terrestrial fluvial-lacustrine system and marking the termination of marine sedimentation in the region. Based on the comprehensive research findings, this study underscores that the superposition, inheritance, and interaction of multiple tectonic events are the primary controls on the paleogeographic architecture and sedimentary. Full article

(This article belongs to the Topic Formation Mechanism and Quantitative Evaluation of Deep to Ultra-Deep High-Quality Reservoirs)

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26 pages, 6729 KB

Open AccessArticle

Integrated Sail–Hull–Turbine Assessment for Wind Power Generation Ship Using Experiment and CFD

by Nguyen Thi Huyen Trang, Taiga Mitsuyuki, Yoshiaki Hirakawa, Thi Pham-Truong and Shun Yokota

J. Mar. Sci. Eng. 2026, 14(2), 111; https://doi.org/10.3390/jmse14020111 - 6 Jan 2026

Abstract

Wind power generation ships (WPG ships), which combine rigid sails for propulsion and underwater turbines for onboard power generation, have attracted increasing attention as a promising concept for utilizing renewable energy at sea. This study presents an integrated assessment of a WPG ship [...] Read more.

Wind power generation ships (WPG ships), which combine rigid sails for propulsion and underwater turbines for onboard power generation, have attracted increasing attention as a promising concept for utilizing renewable energy at sea. This study presents an integrated assessment of a WPG ship by combining towing-tank experiments, CFD simulations using ANSYS Fluent, and theoretical analysis to evaluate the coupled performance of sails, hull, and underwater turbines. First, sail thrust and bare-hull resistance were quantified to identify the effective operating-speed range under Beaufort 6–8 wind conditions, and the optimal number of rigid sails was determined. Based on a thrust–resistance balance at a representative rated operating point, two turbine configurations (two and four turbines) were preliminarily sized. The results show that ten rigid sails can provide near-maximum thrust without excessive aerodynamic interference, and the installation of turbines significantly reduces the feasible operating range compared to the bare-hull case. For the two-turbine configuration, a common effective ship-speed range of 6.58–8.0 m/s is obtained, whereas the four-turbine configuration is restricted to 6.58–7.44 m/s due to wake losses, additional appendage drag, and near-free-surface effects. The four-turbine configuration exhibits approximately 30% lower total power output than the two-turbine configuration. These findings demonstrate that an integrated, system-level evaluation is essential for WPG ship design and indicate that the two-turbine configuration offers a more favorable balance between power generation capability and operational flexibility. Full article

(This article belongs to the Section Ocean Engineering)

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17 pages, 3006 KB

Open AccessArticle

Development of an Early Warning System for Compound Coastal and Fluvial Flooding: Implementation at the Alfeios River Mouth, Greece

by Anastasios S. Metallinos, Michalis K. Chondros, Andreas G. Papadimitriou and Vasiliki K. Tsoukala

J. Mar. Sci. Eng. 2026, 14(2), 110; https://doi.org/10.3390/jmse14020110 - 6 Jan 2026

Abstract

An integrated early warning system (EWS) for compound coastal and fluvial flooding is developed for Pyrgos, Western Greece, where low-lying geomorphology and past storm events highlight the need for rapid, impact-based forecasting. The methodology couples historical and climate-informed metocean and river discharge datasets [...] Read more.

An integrated early warning system (EWS) for compound coastal and fluvial flooding is developed for Pyrgos, Western Greece, where low-lying geomorphology and past storm events highlight the need for rapid, impact-based forecasting. The methodology couples historical and climate-informed metocean and river discharge datasets within a numerical modeling framework consisting of a mild-slope wave model, the CSHORE coastal profile model, and HEC-RAS 2D inundation simulations. A weighted K-Means clustering approach is used to generate representative extreme scenarios, yielding more than 4000 coupled simulations that train and validate Artificial Neural Networks (ANNs). The optimal feed-forward ANN accurately predicts spatially distributed flood depths across the HEC-RAS grid using only offshore wave characteristics, water level, and river discharge as inputs, reducing computation time from hours to seconds. Blind tests demonstrate close agreement with full numerical simulations, with average differences typically below 5% and minor deviations confined to negligible water depths. These results confirm the ANN’s capability to emulate complex compound flooding dynamics with high computational efficiency. Deployed as a web application (EWS_CoCoFlood), the system provides actionable, near-real-time inundation forecasts to support local civil protection authorities. The framework is modular and scalable, enabling future integration of urban and rainfall-induced flooding processes and coastal morphological change. Full article

(This article belongs to the Section Coastal Engineering)

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J. Mar. Sci. Eng., Volume 14, Issue 2 (January-2 2026) – 18 articles

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