Journal of Marine Science and Engineering

20 pages, 2077 KB

Open AccessArticle

Uncovering Coexisting Forward and Inverse Energy Cascades in Oceanic Turbulence via an Energy Cascade Multilayer Directed Network (ECMDN)

by Zengxing Zhang, Junming Jing, Wenze Deng, Beibei Mao, Weihong Ouyang and Chenyang Xue

J. Mar. Sci. Eng. 2026, 14(13), 1256; https://doi.org/10.3390/jmse14131256 - 7 Jul 2026

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Abstract

Multi-scale vortex structures constitute the intrinsic skeleton of turbulent flows and govern the energy cascade process in oceanic turbulence. Elucidating their evolutionary dynamics is crucial for understanding turbulent mixing and transport. In this study, we develop an innovative Energy Cascade Multilayer Directed Network [...] Read more.

Multi-scale vortex structures constitute the intrinsic skeleton of turbulent flows and govern the energy cascade process in oceanic turbulence. Elucidating their evolutionary dynamics is crucial for understanding turbulent mixing and transport. In this study, we develop an innovative Energy Cascade Multilayer Directed Network (ECMDN) framework grounded in complex network theory to directly characterize nonlinear energy coupling pathways and directional transfers among multi-scale vortices in real marine environments. By integrating multi-parameter fusion node definitions, multi-scale interaction detection, and energy transfer direction identification, the ECMDN reconstructs the nonlinear turbulent system into a topologically interpretable structure. The emergent network properties enable quantitative characterization of intermittency and inhomogeneity in the energy cascade, offering new insights into vortex interactions and cross-scale energy transfer mechanisms. Compared with conventional cascade diagnostics including spectral flux, third-order velocity structure functions, multifractal analysis and shell models that require homogeneity and local equilibrium assumptions and only output global averaged energy flux, the proposed ECMDN multilayer network retains point-wise depth coordinates of each vortex interaction, separates directed forward/inverse energy edges, and quantifies intermittency via topological metrics. Analysis of the single Shenhu thermocline shear segment demonstrates these differentiated analytical capabilities of the proposed framework. Application to shear measurements from the Shenhu Sea reveals the simultaneous occurrence of forward and inverse energy cascades, manifesting a synchronous dual-energy-cascade pattern. This indicates that vortices at a given scale can concurrently transfer energy to larger- or smaller-scale structures and receive energy from larger- or smaller-scale counterparts during the cascade process. Our findings observe a typical synchronous dual-energy-cascade pattern in the strong thermocline of the Shenhu Sea, providing a novel theoretical and methodological framework for investigating the spatiotemporal evolution of stratified ocean turbulent mixing and advancing our understanding of geophysical fluid dynamics. Full article

(This article belongs to the Section Physical Oceanography)

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23 pages, 35510 KB

Open AccessArticle

Detection and Defense Against False Data Injection Attacks for Secure Energy Management in Hybrid Electric Ships

by Hao Sun, Na Li, Mo Guo, Jingwei Wei and Tianqing Yuan

J. Mar. Sci. Eng. 2026, 14(13), 1255; https://doi.org/10.3390/jmse14131255 - 7 Jul 2026

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Abstract

Reliable battery state awareness is essential for energy management and power allocation in hybrid electric ships. However, battery management systems are increasingly exposed to False Data Injection Attacks (FDIAs) in intelligent connected environments, which can distort State of Charge (SOC) estimation and compromise [...] Read more.

Reliable battery state awareness is essential for energy management and power allocation in hybrid electric ships. However, battery management systems are increasingly exposed to False Data Injection Attacks (FDIAs) in intelligent connected environments, which can distort State of Charge (SOC) estimation and compromise the operational reliability of shipboard power systems. To address this challenge, this paper proposes a closed-loop “Modeling-Detection-Defense” framework for secure SOC estimation in marine cyber-physical energy systems. First, a stealthy FDIA model is developed based on battery dynamics and physical consistency constraints. Second, a hybrid detection method combining unsupervised and supervised learning is proposed to identify attacks. Finally, a long short-term memory network is employed to reconstruct compromised measurements and provide reliable SOC information for continuous energy management. Experimental results demonstrate that the proposed framework mitigates SOC estimation deviations caused by FDIAs. In addition, it effectively reduces power allocation errors and energy losses, thereby improving the cyber-resilience, operational reliability, and energy efficiency of hybrid ship power systems. Full article

(This article belongs to the Special Issue Advancements in Hybrid Power Systems for Marine Applications)

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15 pages, 3628 KB

Open AccessArticle

Age and Growth of Pointhead Flounder, Cleistenes pinetorum, in the West Sea of Korea

by Dong Hyuk Choi, Seulhee Lee, Dae Hyeon Kwon and Soo Jeong Lee

J. Mar. Sci. Eng. 2026, 14(13), 1254; https://doi.org/10.3390/jmse14131254 - 7 Jul 2026

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Abstract

To investigate the age and growth characteristics of the pointhead flounder (Cleisthenes pinetorum) in the West Sea (Yellow Sea) of Korea, samples were collected from bottom trawl vessels throughout 2019. A total of 1116 individuals (1015 females and 101 males) were [...] Read more.

To investigate the age and growth characteristics of the pointhead flounder (Cleisthenes pinetorum) in the West Sea (Yellow Sea) of Korea, samples were collected from bottom trawl vessels throughout 2019. A total of 1116 individuals (1015 females and 101 males) were analyzed. Because specimens were obtained from commercial landings, only fish of approximately 20 cm or larger were available due to marketability constraints. The body weight (BW) − total length (TL) relationships were BW = 0.00001TL^3.3443 (R² = 0.9279) for females and BW = 0.000002TL^3.2659 (R² = 0.9347) for males. The observed sex ratio (male:female = 1:10) was strongly female-biased; however, this likely reflected the underrepresentation of smaller males in commercial catches rather than the natural population structure. Females also exhibited larger body lengths than males. Otoliths were generally round, with a slightly elongated anterior region, and measurements were taken along the longest axis from the core to the margin. The relationship between TL and otolith radius (R) was expressed as TL = 8.0342R + 5.6218 (R² = 0.8408). Growth equations were estimated for both sexes; however, because older males were poorly represented, the male von Bertalanffy growth function was fitted with the asymptotic length fixed to 43.3 cm (110% of the observed maximum male TL). Annuli were formed annually in November, and the spawning season was identified as September–November, suggesting a close association between annulus formation and the spawning period. The von Bertalanffy growth equations were Lt = 57.66(1 − exp[−0.1865(t + 0.46)]) for females and Lt = 43.3(1 − exp[−0.2679(t + 0.5490)]) for males. Full article

(This article belongs to the Section Marine Biology)

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17 pages, 8845 KB

Open AccessArticle

Temporal Changes and Simulation of Tropical Cyclone Risk Assessment in the Guangdong–Hong Kong–Macao Greater Bay Area

by Manli Zheng, Mingli Zhao and Xianwu Shi

J. Mar. Sci. Eng. 2026, 14(13), 1253; https://doi.org/10.3390/jmse14131253 - 7 Jul 2026

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Abstract

This study develops a systematic framework for assessing the temporal dynamics of tropical cyclone (TC) risk in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) from 2013 to 2023. A unified composite index was constructed by integrating hazard, vulnerability, and mitigation capacity, allowing for [...] Read more.

This study develops a systematic framework for assessing the temporal dynamics of tropical cyclone (TC) risk in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) from 2013 to 2023. A unified composite index was constructed by integrating hazard, vulnerability, and mitigation capacity, allowing for the quantification of the interannual evolution of TC risk. The analysis showed that maximum storm surge and extreme precipitation drove hazard variability, with distinct peaks during the super typhoons of 2017 and 2018. In the vulnerability dimension, GDP and population density together accounted for over 50% of the total weight, and the vulnerability index shows an upward trend, though its growth slowed in 2020. Mitigation capacity improved steadily, accelerating after 2020 and partly offsetting the risk pressure from growing vulnerability. The risk index broadly mirrored the hazard index, peaking in 2018. Notably, in the two TC-free years (2014 and 2019), the risk index was higher in 2019 than in 2014, reflecting an increased vulnerability-to-mitigation ratio over the intervening period. A coherence check against three disaster loss indicators (2018–2023) yielded a correlation of r = 0.8, indicating broad consistency in the interannual patterns of the risk index and observed losses. This study provides a temporally explicit baseline for understanding recent TC risk dynamics and offers methodological support for resilience planning in coastal megaregions facing climate-related hazards. Full article

(This article belongs to the Section Ocean and Global Climate)

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27 pages, 6275 KB

Open AccessArticle

Intelligent Vessels Localization Based on Adaptive Correlation Information Filter Network in Complex Marine and Port Environments

by Lei Yan, Wei Zeng, Zhixin Xia, Bo Meng, Junli Ge and Deming Kong

J. Mar. Sci. Eng. 2026, 14(13), 1252; https://doi.org/10.3390/jmse14131252 - 7 Jul 2026

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Abstract

Accurate and robust localization is essential for intelligent vessels operating in complex marine and port environments. However, single-sensor localization is often affected by limited observation range, environmental occlusion, local interference, and sensor degradation. Although multi-sensor fusion can improve localization reliability, unknown cross-correlated measurement [...] Read more.

Accurate and robust localization is essential for intelligent vessels operating in complex marine and port environments. However, single-sensor localization is often affected by limited observation range, environmental occlusion, local interference, and sensor degradation. Although multi-sensor fusion can improve localization reliability, unknown cross-correlated measurement noise arising from shared disturbances, time synchronization errors, communication delays, and inconsistent fusion rates may degrade traditional information-filter-based fusion methods. To address this problem, this paper proposes an Adaptive Correlation Information Filter Network (ACIFNet) for multi-sensor fusion localization of intelligent vessels. ACIFNet preserves the recursive structure of the extended information filter and uses a Transformer-based network to learn adaptive information-domain fusion weights, thereby compensating for unknown inter-sensor correlations without explicitly estimating the full correlation covariance matrix. Experiments on constant-velocity, coordinated-turn (CV), and three-degree-of-freedom vessel motion models, together with a real-world restricted-waterway dataset, demonstrate that ACIFNet achieves higher localization accuracy and stability than Edge Incorporative Fusion (EIF)-inexact fusion, measurement fusion, and KalmanNet. In the CV and three-degree-of-freedom experiments, ACIFNet reduces the mean RMSE by 48.7%, 23.2%, and 26.1%, respectively, compared with KalmanNet. On the real-world dataset, ACIFNet achieves a mean position error of 9.90 m, an RMSE of 11.24 m, and a cross-track error of 8.72 m. These results show that ACIFNet effectively combines the interpretability of information filtering with the adaptive representation capability of neural networks for robust multi-sensor fusion localization under unknown cross-correlated measurement noises. Full article

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19 pages, 7545 KB

Open AccessArticle

Morphodynamics of Reed-Dominated Phytogenic Shores of the Dniprovsko–Buzky Liman (Black Sea, Ukraine)

by Andriy Cherniavskiy, Yuliia Shevchuk and Oleksiy Davydov

J. Mar. Sci. Eng. 2026, 14(13), 1251; https://doi.org/10.3390/jmse14131251 - 7 Jul 2026

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Abstract

The paper examines the morphodynamic development of reed-dominated phytogenic shores of the Dniprovsko–Buzky Liman, the largest river-mouth system in the northwestern Black Sea region. Based on field observations and analysis of Landsat and Sentinel satellite imagery acquired during 1985–2025, the spatial distribution of [...] Read more.

The paper examines the morphodynamic development of reed-dominated phytogenic shores of the Dniprovsko–Buzky Liman, the largest river-mouth system in the northwestern Black Sea region. Based on field observations and analysis of Landsat and Sentinel satellite imagery acquired during 1985–2025, the spatial distribution of phytogenic shores, long-term dynamics of the external vegetation boundary, and moisture characteristics of the depositional substrate were investigated. The results revealed the predominance of progradational trends accompanied by pronounced spatial heterogeneity of morphodynamic processes. Variations in surface moisture were analyzed as an indirect indicator of substrate conditions potentially associated with long-term phytogenic shore development. The obtained results suggest that phytogenic shores should be considered complex biogeomorphological systems whose evolution is controlled by the interaction of hydrodynamic, lithodynamic and biotic factors. Full article

(This article belongs to the Section Coastal Engineering)

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33 pages, 6262 KB

Open AccessArticle

Parametric Modeling and Hydrodynamic Analysis of Bio-Inspired Propellers with Position- and Height-Controllable Leading-Edge Tubercles

by Yufan Cao, Xiaoyi An, Chengshan Li, Jie Bai, Liuzhen Ren, Yuanchao Gao and Zejun Song

J. Mar. Sci. Eng. 2026, 14(13), 1250; https://doi.org/10.3390/jmse14131250 - 6 Jul 2026

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Abstract

Leading-edge tubercles provide a bio-inspired modification for regulating the hydrodynamic performance of marine propellers, but their controllable generation on complex three-dimensional blades remains insufficiently studied. This study develops a parametric modeling method for tubercled leading-edge propellers based on the David Taylor Model Basin [...] Read more.

Leading-edge tubercles provide a bio-inspired modification for regulating the hydrodynamic performance of marine propellers, but their controllable generation on complex three-dimensional blades remains insufficiently studied. This study develops a parametric modeling method for tubercled leading-edge propellers based on the David Taylor Model Basin (DTMB) 4383 geometry. The method combines B-spline smooth reconstruction with a Gaussian envelope function to control tubercle radial peak position and height. After validation with publicly available open-water experimental data, the computational fluid dynamics (CFD) method is applied to uniform and locally targeted tubercled models. The results show that leading-edge tubercles modify the suction-side low-pressure region and redistribute local blade loading. The radial peak position mainly controls the concentration region of the pressure disturbance, whereas peak height affects its intensity. At the design advance coefficient, moving the target peak from r/R = 0.26 to r/R = 0.92 decreased the thrust coefficient by 0.77% and increased the torque coefficient by 1.75%. For a fixed target position, increasing the maximum amplitude ratio from 0.05 to 0.80 increased the thrust and torque coefficients by 0.25% and 0.88%, respectively. These findings indicate that tubercle design should balance radial position and protrusion height. Full article

(This article belongs to the Special Issue Overall Design of Underwater Vehicles)

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1 pages, 143 KB

Open AccessCorrection

Correction: Hou et al. Spatiotemporal Deep Learning to Forecast Storm Surge Water Levels and Storm Trajectory: Case Study Hurricane Harvey. J. Mar. Sci. Eng. 2025, 13, 1780

by Junqin Hou, Muhammad K. Akbar, Manar D. Samad and Lizhi Ouyang

J. Mar. Sci. Eng. 2026, 14(13), 1249; https://doi.org/10.3390/jmse14131249 - 6 Jul 2026

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Abstract

In the original publication [...] Full article

28 pages, 986 KB

Open AccessArticle

Key Risk Factor Identification for Deep-Sea Transportation Safety Based on Complex Network Theory

by Kun Lang, Xia Liu, Lin Li and Ming Zhong

J. Mar. Sci. Eng. 2026, 14(13), 1248; https://doi.org/10.3390/jmse14131248 - 6 Jul 2026

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Abstract

Deep-sea transportation is faced with complex navigation environments, long voyages, limited emergency response resources, and interacting safety risks. Existing studies have mainly focused on individual risk factors, while the correlations and coupling effects among different factors have received insufficient attention. To identify the [...] Read more.

Deep-sea transportation is faced with complex navigation environments, long voyages, limited emergency response resources, and interacting safety risks. Existing studies have mainly focused on individual risk factors, while the correlations and coupling effects among different factors have received insufficient attention. To identify the key risk factors affecting deep-sea transportation safety, this paper proposes a novel key factor identification model based on complex network theory. Firstly, 34 risk factors affecting deep-sea transportation safety are selected from five aspects using a literature analysis method. Secondly, a weighted directed network of risk factors is constructed based on complex network theory. Then, to evaluate the node importance, six node importance evaluation indicators are established, and a node importance evaluation method is proposed by integrating the analytic hierarchy process (AHP), technique for order preference by similarity to an ideal solution (TOPSIS), and gray relational analysis (GRA). Key risk factors are then determined according to the node importance evaluation results. Finally, the effectiveness of the proposed model is verified through a case study. The results show that the top five most critical risk factors are risk of leakage, emergency speed, physical and chemical properties of the cargoes, sense of personnel safety duty, and seasonal route. The findings can provide practical support for maritime authorities, shipping companies, and safety managers in formulating targeted prevention, control, and emergency response measures for deep-sea transportation safety. Full article

(This article belongs to the Section Ocean Engineering)

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28 pages, 18713 KB

Open AccessArticle

Propagation-Time-Consistent Ray-Path Correction for Long-Baseline Underwater Acoustic Localization

by Zhichao Lv, Siyuan Wang, Libin Du, Gang Wang, Kaiyan Han, Fei Yu and Guoli Song

J. Mar. Sci. Eng. 2026, 14(13), 1247; https://doi.org/10.3390/jmse14131247 - 5 Jul 2026

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Abstract

Non-uniform sound velocity profiles (SVPs) cause sound-ray refraction and propagation-path bending. The straight-line mapping among propagation time, propagation distance, and target position is, therefore, disrupted, leading to systematic errors in constant-sound-speed localization. To improve the consistency between propagation correction and geometric localization, an [...] Read more.

Non-uniform sound velocity profiles (SVPs) cause sound-ray refraction and propagation-path bending. The straight-line mapping among propagation time, propagation distance, and target position is, therefore, disrupted, leading to systematic errors in constant-sound-speed localization. To improve the consistency between propagation correction and geometric localization, an iterative ray-path correction method based on propagation-time consistency is proposed. The method contains three coupled steps. First, a path-dependent local layered SVP model is constructed for each target-to-base-station path, rather than using a global or fixed sound-speed model. Second, the ray parameter is inverted under the constraint of measured time-of-arrival (TOA), so that the corrected ray path remains consistent with the observed propagation time. Third, the corrected slant range obtained by layered ray tracing is fed back into a known-depth weighted least squares (WLS) localization model, forming a closed-loop position update. The method is evaluated through long-baseline (LBL) simulations with multiple SVPs and propagation geometries and is validated using measured TOA data and an observation-derived SVP. The simulation results show that sub-meter accuracy can be achieved under the tested TOA-noise conditions. In measured-data validation, the planar localization error is reduced from 4.6866 m to 0.1923 m. No divergence is observed in the tested small SVP-perturbation cases. Full article

(This article belongs to the Section Ocean Engineering)

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33 pages, 4938 KB

Open AccessArticle

Multi-UUV Encirclement with Risk-Driven Coordination Point Allocation

by Jingxiang Feng, Di Zhao, Chengcheng Qiu, Peng Chang and Jingwei Dong

J. Mar. Sci. Eng. 2026, 14(13), 1246; https://doi.org/10.3390/jmse14131246 - 4 Jul 2026

Viewed by 308

Abstract

Cooperative encirclement using multiple unmanned underwater vehicles (UUVs) is a critical task in underwater base defense, yet existing approaches typically rely on static risk rules that cannot fuse multi-source information dynamically and decouple coordination-point allocation from live risk assessment, limiting adaptive response in [...] Read more.

Cooperative encirclement using multiple unmanned underwater vehicles (UUVs) is a critical task in underwater base defense, yet existing approaches typically rely on static risk rules that cannot fuse multi-source information dynamically and decouple coordination-point allocation from live risk assessment, limiting adaptive response in evolving adversarial conditions. To address these limitations, this paper proposes a continuous risk-driven adaptive weighting strategy for coordination-point allocation, which dynamically adjusts evaluation metric weights as a smooth function of real-time Bayesian risk intensity, enabling seamless transitions between time-efficiency-oriented and synchronization-oriented encirclement modes without discrete switching. This strategy is embedded within a closed-loop decision framework that integrates a Bayesian network for dynamic risk quantification and an online corner-based deployment model to guarantee continuous execution feasibility from approach to final task completion. Simulations validate that the proposed framework ensures stable, adaptive encirclement as risk levels evolve dynamically throughout the mission. Compared to the greedy priority-based allocation and the time-balance allocation as conventional baselines, the proposed strategy reduces task completion time by up to 22.8% and 9.5%, respectively, demonstrating strong robustness in dynamic, uncertain environments. Full article

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16 pages, 5840 KB

Open AccessArticle

Abnormal Data Elimination-Based Underwater 3D Magnetic Induction Localization Method

by Meiyan Zhang, Ning Zhang, Niaz Ahmed, Zhou Yu and Wenyu Cai

J. Mar. Sci. Eng. 2026, 14(13), 1245; https://doi.org/10.3390/jmse14131245 - 4 Jul 2026

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Abstract

To address the problem of three-dimensional (3D) localization in underwater environments, this paper proposes a 3D positioning method based on magnetic induction communication (MI in short). Dual transmitters equipped with 3D coils are used to transmit magnetic field signals, while a single receiver [...] Read more.

To address the problem of three-dimensional (3D) localization in underwater environments, this paper proposes a 3D positioning method based on magnetic induction communication (MI in short). Dual transmitters equipped with 3D coils are used to transmit magnetic field signals, while a single receiver with 3D coils is adopted to receive signals. Three-dimensional position calculation is realized by collecting induced voltage from the receiving 3D coils, which enables any device at a known position in space to provide positioning services for other devices. To eliminate abnormal data and suppress environmental noise interference in underwater received signals and further improve positioning performance, an improved density clustering algorithm named the Density-Based Spatial Clustering Method in Magnetic Positioning is proposed to remove erroneous positioning data. In addition, Kalman filtering is introduced to jointly suppress environmental noise interference. Experimental results demonstrate that the average positioning error of the proposed localization method is 0.67 m and maximum positioning error is 0.83 m; therefore, this paper provides a novel technical solution for underwater positioning in non-line-of-sight environments. Full article

(This article belongs to the Section Ocean Engineering)

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15 pages, 707 KB

Open AccessArticle

The Fatigue Load Analysis of Wind Turbines in a Reconfigurable Floating Offshore Wind Farm

by Mohammad Mahdi Malayeri, Yue Niu and Ryozo Nagamune

J. Mar. Sci. Eng. 2026, 14(13), 1244; https://doi.org/10.3390/jmse14131244 - 4 Jul 2026

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Abstract

This paper analyzes the fatigue loads of wind turbines in a floating offshore wind farm (FOWF) whose layout can be reconfigured. Such wind farm reconfiguration will be useful for wake effect mitigation in varying wind conditions. As an example FOWF, a farm with [...] Read more.

This paper analyzes the fatigue loads of wind turbines in a floating offshore wind farm (FOWF) whose layout can be reconfigured. Such wind farm reconfiguration will be useful for wake effect mitigation in varying wind conditions. As an example FOWF, a farm with three 5 MW floating offshore wind turbine (FOWT) models on semi-submersible platforms, developed by the National Laboratory of the Rockies (NLR) (formerly the National Renewable Energy Laboratory (NREL)), is considered. Simulations for the example FOWF are conducted with various realistic turbulent wind and irregular wave conditions in the medium-fidelity wind farm simulator FAST.Farm. Using the simulation data, fatigue analysis is conducted by calculating the damage equivalent loads (DELs) using the computational tool MLife at critical components of the three FOWTs. The analysis results demonstrate the potential of reconfigurable FOWFs in not only increasing power outputs but also reducing fatigue loads for many critical components of turbines. Full article

(This article belongs to the Section Ocean Engineering)

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18 pages, 9666 KB

Open AccessArticle

Docking Collision Response of an Underwater Mooring Suspension Docking System

by Hua Tan, Zhen Lv, Rong Zheng and Guangzhi Zhang

J. Mar. Sci. Eng. 2026, 14(13), 1243; https://doi.org/10.3390/jmse14131243 - 4 Jul 2026

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Abstract

Suspension docking systems offer significant application potential in autonomous underwater docking operations because of their deployment and recovery convenience. This study investigated the interaction between an axisymmetric, underactuated autonomous underwater vehicle (AUV) and a suspended guiding hood docking device (DOCK). The effects of [...] Read more.

Suspension docking systems offer significant application potential in autonomous underwater docking operations because of their deployment and recovery convenience. This study investigated the interaction between an axisymmetric, underactuated autonomous underwater vehicle (AUV) and a suspended guiding hood docking device (DOCK). The effects of collision velocity, collision location, collision angle, mass, and moment of inertia on the post-collision kinematic states of both bodies are analyzed. Previous studies have typically determined AUV parameters using empirical formulas, whereas few have clearly described the calibration procedure for the hydrodynamic drag coefficients of a suspended guiding hood DOCK. In this study, the hydrodynamic coefficients of both the AUV and the DOCK were determined using STAR-CCM+ and embedded into the ADAMS built-in functions to construct a physically more realistic simulation model. Subsequently, water tank experiments were conducted for suspension docking collisions. The validity of the simulation model was verified by comparing the kinematic states of the DOCK and AUV observed from the simulations and experiments. Based on the established model, the docking dynamics under various operating conditions were simulated. The simulation results indicate that the AUV mass should not exceed twice the mass of the DOCK, and the moment of inertia of the DOCK should be maximized. The risk of suspension docking failure increases significantly when the mooring line length exceeds 40 m, and the negative buoyancy of the DOCK should be at least 300 N. These findings provide critical guidance for improving the success rate of suspension docking operations. Full article

(This article belongs to the Section Ocean Engineering)

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18 pages, 28821 KB

Open AccessArticle

Distribution Characteristics and Evolution Mechanism of Pockmark Group in the Northwestern Xisha Uplift, South China Sea

by Tianqi Lu, Yanfu Yao, Lushan Wu, Xuelin Li, Lei Huang and Xuanyu Bai

J. Mar. Sci. Eng. 2026, 14(13), 1242; https://doi.org/10.3390/jmse14131242 - 4 Jul 2026

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Abstract

Submarine pockmarks are typical seafloor micro-geomorphic landforms formed by deep fluid seepage and sediment erosional processes. Based on high-resolution multibeam bathymetric data, multi-channel seismic sections and sediment core data, the present study systematically investigates 64 pockmarks in the northwestern Xisha Uplift, focusing on [...] Read more.

Submarine pockmarks are typical seafloor micro-geomorphic landforms formed by deep fluid seepage and sediment erosional processes. Based on high-resolution multibeam bathymetric data, multi-channel seismic sections and sediment core data, the present study systematically investigates 64 pockmarks in the northwestern Xisha Uplift, focusing on their distribution, morphology and genetic mechanisms. These pockmarks exhibit a NE–SW zonal distribution, concentrated in the 1200–1600 m central slope transition zone, and are classified into circular–elliptical, crescentic and elongated types with distinct morphometric variability. Vertically, the T40 unconformity defines the stratified geological architecture: underlying carbonate uplifts and karst-fracture systems act as fluid reservoirs and migration conduits, while overlying Late Miocene–Quaternary fine-grained hemipelagic sediments form a low-permeability caprock. Fluid overpressure accumulation and hydraulic fracturing of the caprock trigger initial pockmark formation, while spatial heterogeneity of surficial sediments and bottom-current reworking control morphological differentiation. The present study clarifies the coupled controls of deep tectono-fluid activities and shallow sedimentary and hydrodynamic processes on pockmark evolution, establishing a refined dynamic model to address the research gap regarding pockmark group genesis in the study area. Full article

(This article belongs to the Special Issue Advances in Sedimentology and Coastal and Marine Geology, 3rd Edition)

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19 pages, 3560 KB

Open AccessArticle

Optimization Design of Floating Offshore Platforms Based on the Parallel EGO Algorithm

by Shigang Wang and Fuqiang Luo

J. Mar. Sci. Eng. 2026, 14(13), 1241; https://doi.org/10.3390/jmse14131241 - 3 Jul 2026

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Abstract

Floating offshore platforms are subjected to significant impact loads from ocean currents, which pose considerable challenges to the safety of floating offshore wind turbines. To address this issue, this study develops a novel infill criterion framework based on the parallel Efficient Global Optimization [...] Read more.

Floating offshore platforms are subjected to significant impact loads from ocean currents, which pose considerable challenges to the safety of floating offshore wind turbines. To address this issue, this study develops a novel infill criterion framework based on the parallel Efficient Global Optimization (EGO) algorithm. Compared with the traditional EGO algorithm, the proposed framework enables the simultaneous addition of multiple infill samples in each iteration, resulting in substantially improved optimization efficiency. The proposed method is applied to the optimization of floating offshore platforms, where drag minimization is considered the primary design objective. The results demonstrate that incorporating the mean squared error (MSE) criterion into the conventional EGO algorithm, while constraining the search space of the MSE criterion, effectively accelerates the convergence of the Expected Improvement (EI) criterion. Furthermore, an optimization method for floating platforms is established, leading to a reduction in drag of approximately 1.69% after optimization. The proposed optimization framework improves the drag performance of floating offshore platforms and provides a new approach for structural optimization in offshore engineering. Full article

(This article belongs to the Special Issue Optimized Design of Offshore Wind Turbines)

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44 pages, 46825 KB

Open AccessReview

External Water Pressure Assessment on Initial Support in Drill-and-Blast Subsea Tunnels: A Comprehensive Review

by Sartaj Hussain, Javid Hussain, Sheng Qian and Lan Cui

J. Mar. Sci. Eng. 2026, 14(13), 1240; https://doi.org/10.3390/jmse14131240 - 3 Jul 2026

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Abstract

Subsea tunnels constructed by the drill-and-blast method are increasingly required in modern infrastructure and are often exposed to high groundwater pressure and fractured rock conditions. In such environments, external water pressure acting on initial support strongly affects tunnel stability, durability, and construction safety. [...] Read more.

Subsea tunnels constructed by the drill-and-blast method are increasingly required in modern infrastructure and are often exposed to high groundwater pressure and fractured rock conditions. In such environments, external water pressure acting on initial support strongly affects tunnel stability, durability, and construction safety. Because the initial support is temporary, discontinuous, and prone to cracking, evaluation of its water pressure response remains challenging. Current design practice relies on simplified assumptions and empirical approaches, inadequate for fractured rock masses under high water pressure. This review synthesizes research on external water pressure in tunnels, with emphasis on drill-and-blast subsea tunnels. Empirical reduction coefficient methods, theoretical analytical solutions, numerical techniques, and physical model testing are critically examined in terms of their theoretical basis, applicability, and limitations. Special attention is given to seepage behavior in fractured rock masses, including single-fracture seepage laws, equivalent continuum models, and discrete fracture network approaches, and their ability to represent fracture-controlled flow and water pressure redistribution. The review shows that conventional seepage or seepage–stress coupled methods are insufficient to capture stress redistribution, fracture evolution, and damage-induced permeability changes governing water pressure behavior. By contrast, advanced coupled stress–seepage–damage and stress–seepage–fracturing models provide more physically consistent frameworks for analyzing external water pressure acting on initial support. In addition, hydro-mechanical discrete lattice models are reviewed as a promising meso-scale framework for capturing crack initiation, crack coalescence, and crack-controlled seepage paths that may govern localized external water pressure redistribution behind initial support. However, their application to subsea tunnels remains limited, and current design codes still lack unified calculation methods. Major challenges remain, including the lack of consistent definitions of external water pressure, inadequate consideration of the interaction between tunnel support and surrounding rock, and insufficient validation through laboratory experiments and field observations. Future research should develop mechanism-based methods supported by monitoring and validation to improve subsea tunnel safety. Full article

(This article belongs to the Special Issue Disaster Prevention and Control of Subsea Structures)

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30 pages, 3002 KB

Open AccessArticle

Channel-Adaptive Joint Selection of FEC Scheme, Rate, and Segment Size for Short-Block Underwater Acoustic Communication

by Seunggyu Kim, Saeyong Park and Taeho Im

J. Mar. Sci. Eng. 2026, 14(13), 1239; https://doi.org/10.3390/jmse14131239 - 3 Jul 2026

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Abstract

Underwater acoustic (UWA) sensor and control links carry mostly short messages (below ∼10 kB) over time-varying, low-SNR multipath channels, which is a regime where forward error correction (FEC) operates on short, finite blocks where a single static configuration is inefficient. Adaptive schemes for [...] Read more.

Underwater acoustic (UWA) sensor and control links carry mostly short messages (below ∼10 kB) over time-varying, low-SNR multipath channels, which is a regime where forward error correction (FEC) operates on short, finite blocks where a single static configuration is inefficient. Adaptive schemes for these links typically adjust the modulation order and code rate; the payload segment (block) size—which, together with the code rate, sets the coded block length that governs the finite-blocklength penalty for short messages—is seldom adapted per transmission jointly with the choice of FEC scheme on a like-for-like footing. We propose a per-transmission controller that jointly selects the FEC scheme, code rate, and segment size from a prediction of the near-term channel state, which is paired with a like-for-like short-block benchmark of LDPC, list-decoded polar, BCH, Reed–Solomon, convolutional, and turbo codes. No single code dominates: under a unified ARQ goodput metric, the reliability–throughput frontier has a crossover that shifts with the channel, so the optimal FEC choice is channel-dependent. Across our experiments, the segment-size degree of freedom is the dominant throughput lever, capturing essentially all of the adaptation gain at low-to-mid SNR and over fading; switching the FEC family adds a further, bounded gain only where the frontier crosses between families (up to 10% at high-SNR AWGN, polar to RS). The joint controller essentially matches a fair single-family adaptive baseline off the crossover (to within a negligible prediction-overhead margin) and exceeds it at that crossover, beats a fixed, no-CSI code by up to 16%, and captures 91–99% of an oracle; a lightweight persistence predictor matches a learned LSTM for the first-order channel-state model studied. A statistics-driven replay using measured-channel parameters, and a recorded-channel replay over the public Watermark benchmark, preserve the same family ordering. Full article

(This article belongs to the Section Ocean Engineering)

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22 pages, 3499 KB

Open AccessArticle

Numerical Study on the Multiphase Flow and Motion Characteristics of an Underwater Hypervelocity Vehicle During the Acceleration Process

by Menghao Wang, Chenxi Zhang and Peng Wang

J. Mar. Sci. Eng. 2026, 14(13), 1238; https://doi.org/10.3390/jmse14131238 - 3 Jul 2026

Viewed by 310

Abstract

To investigate the coupled evolution of cavity morphology, hydrodynamic characteristics, and motion behavior during the wide-speed-range acceleration of an underwater hypervelocity vehicle, a numerical framework for supercavitating multiphase flow was established by coupling the Improved Delayed Detached Eddy Simulation (IDDES) turbulence model, the [...] Read more.

To investigate the coupled evolution of cavity morphology, hydrodynamic characteristics, and motion behavior during the wide-speed-range acceleration of an underwater hypervelocity vehicle, a numerical framework for supercavitating multiphase flow was established by coupling the Improved Delayed Detached Eddy Simulation (IDDES) turbulence model, the Schnerr–Sauer cavitation model, and the Volume of Fluid (VOF) method. Combined with the overset mesh technique and the DFBI six-degree-of-freedom model, the multiphase flow and motion characteristics during acceleration were systematically studied. The results show that the ventilated cavity strongly compresses the natural cavity, leading to a complex gas–vapor–liquid three-phase coexistence structure in the mid-body conical section and stern region, with the ventilated cavity eventually becoming dominant. The drag coefficient exhibits a three-stage evolution associated with cavity development over the conical section, cylindrical section, and the final formation of a supercavity. Once the vehicle is enveloped by the supercavity, pressure drag becomes dominant. Ventilation timing significantly affects supercavity formation and flow stability. Low-speed ventilation reduces drag earlier but prolongs the three-phase coexistence period and cavity formation process, whereas high-speed ventilation promotes the rapid formation of a stable supercavity. The supercavity formation time reaches 0.5 s under ventilation at 30 m/s, which is more than twice the value for ventilation at 70 m/s. Full article

(This article belongs to the Section Ocean Engineering)

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23 pages, 7972 KB

Open AccessArticle

Onshore U-OWC Wave Energy Converter: A Hydrodynamic Study of Its Capture Performance Impacted by Air-Compressibility Effects

by Yi-Chih Chow, Hong-Yang Chang, Duy Tong Nguyen and Chen-Chou Lin

J. Mar. Sci. Eng. 2026, 14(13), 1237; https://doi.org/10.3390/jmse14131237 - 3 Jul 2026

Viewed by 1155

Abstract

The distinct engineering advantages of Oscillating Water Column (OWC) systems have driven substantial academic interest lately. This work examines the onshore U-shaped OWC (U-OWC), selected for its cost-effective installation integrated with existing coastal infrastructure and its superior broadband response to diverse wave climates. [...] Read more.

The distinct engineering advantages of Oscillating Water Column (OWC) systems have driven substantial academic interest lately. This work examines the onshore U-shaped OWC (U-OWC), selected for its cost-effective installation integrated with existing coastal infrastructure and its superior broadband response to diverse wave climates. Time-domain CFD simulations, incorporating the scaling-rematched approach, were conducted to quantify key hydrodynamic and air-compressibility coefficients, including the amplitude of the wave exciting force, fluid damping coefficient, added mass, absorption factor, and the effective PTO (power take-off) damping and air-compressibility coefficients. These parameters collectively elucidate the underlying hydrodynamics and how they are interwoven with the compressibility of the air in the plenum chamber, thereby impacting the U-OWC’s energy-capture performance under incident waves. A principal finding is the identification of a C+ interval wherein air compressibility enhances capture performance in the lower wave-period range examined (<8.0 s). The added mass of the present U-OWC exhibits a remarkably pronounced decrease around the wave period of 8.0 s, which can be verified by a simple resonance formula of heave buoys to underline its strong near-resonance behavior. Full article

(This article belongs to the Special Issue Design, Modeling, and Development of Marine Renewable Energy Devices)

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18 pages, 5075 KB

Open AccessArticle

Seasonal Expansion and Spatial Concentration in Arctic Shipping: A Data-Driven Analysis Using the Arctic Traffic Intensity Framework

by Pedro Coelho Terossi, Yuri Alexandre Meyer and Rafael Henrique de Oliveira

J. Mar. Sci. Eng. 2026, 14(13), 1236; https://doi.org/10.3390/jmse14131236 - 3 Jul 2026

Viewed by 479

Abstract

The rapid cryospheric transformation of the Arctic presents complex challenges for global supply chains, necessitating data-driven decision-making frameworks to optimize route planning and resource allocation. Standard aggregate statistics fail to capture the structural nuances required for operational research models in this evolving landscape. [...] Read more.

The rapid cryospheric transformation of the Arctic presents complex challenges for global supply chains, necessitating data-driven decision-making frameworks to optimize route planning and resource allocation. Standard aggregate statistics fail to capture the structural nuances required for operational research models in this evolving landscape. This study analyzes the spatiotemporal dynamics of Arctic navigation intensity to determine the extent of the operational window expansion and the spatial displacement of shipping routes. We deployed the Arctic Traffic Intensity Framework (ATIF) to generate a high-resolution spatiotemporal dataset spanning 2012–2024. To address variance instability and inform strategic forecasting, a log-linear regression model was applied to calculate the Annual Percentage Change, allowing for a dual analysis of absolute linear trends (volume) versus relative growth (proportional intensity) across heterogeneous baselines. A bilateral expansion of the high-intensity window to nearly five months (June–October) was observed, driven by earlier spring break-up and delayed autumn freeze-up. Spatially, the geometric navigational centroid has shifted southwestward, highlighting a concentration of activity in the Barents and Kara Seas rather than a uniform Transpolar dispersion. It can be concluded that the Arctic shipping system has transitioned from a seasonally restricted frontier to a standardized resource extraction corridor. However, the traffic is heavily clustered in the western sector, creating high-density logistic bottlenecks rather than a homogenized international transit route. Full article

(This article belongs to the Section Ocean Engineering)

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24 pages, 6231 KB

Open AccessArticle

Dynamic Evolution Mechanisms and Lateral Spreading Prediction of Coral Sand Particle Clouds in Still Water

by Jie Chen, Feifei Li, Xueying Liu, Changbo Jiang, Zhiyuan Wu and Zhen Yao

J. Mar. Sci. Eng. 2026, 14(13), 1235; https://doi.org/10.3390/jmse14131235 - 2 Jul 2026

Viewed by 273

Abstract

Coral sands are critical in the construction of islands and harbors in tropical regions. Studying their dispersal, specifically the movement of ‘sedimentary clouds’ during marine dumping/dredging operations, is essential for optimizing construction efficiency and mitigating impacts on marine ecosystems. This study investigates the [...] Read more.

Coral sands are critical in the construction of islands and harbors in tropical regions. Studying their dispersal, specifically the movement of ‘sedimentary clouds’ during marine dumping/dredging operations, is essential for optimizing construction efficiency and mitigating impacts on marine ecosystems. This study investigates the evolutionary characteristics of coral sand particles in still water via controlled indoor experiments. By manipulating parameters such as particle size, mass, nozzle diameter, and air release height, this study evaluated the impact of aspect ratio, Stokes number, and initial particle momentum on the movement of coral sand clouds. The results indicate that variations in air release height modulated the cloud’s width and corresponding diffusion angle, but exerted a negligible impact on the cloud front’s velocity and position. Empirical formulas for traditional quartz sand have limitations in reflecting the complex hydrodynamic settling behavior of coral sand. To address this, this paper establishes a modified empirical equation. This equation effectively predicts the width of coral sand plumes across different air release heights and Stokes number ranges. Furthermore, rather than directly quantifying microscopic morphological features, this study interprets these macroscopic transport characteristics from a process-based hydrodynamic perspective. Ultimately, the resulting predictive data and empirical framework provide a practical reference for evaluating sediment dispersion in reef engineering projects. Full article

(This article belongs to the Section Coastal Engineering)

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26 pages, 1764 KB

Open AccessArticle

Drivers of Coastal Water Quality and Ecological Status in the Bothnian Sea: Phosphorus Dynamics Across Scales

by Harri Helminen

J. Mar. Sci. Eng. 2026, 14(13), 1234; https://doi.org/10.3390/jmse14131234 - 2 Jul 2026

Viewed by 299

Abstract

Coastal water quality in the Bothnian Sea is shaped by interactions among local nutrient inputs, internal nutrient cycling, and basin-scale phosphorus enrichment, complicating the assessment and management of eutrophication. This study analyses long-term time series of nutrients (total phosphorus (TP), dissolved inorganic phosphorus [...] Read more.

Coastal water quality in the Bothnian Sea is shaped by interactions among local nutrient inputs, internal nutrient cycling, and basin-scale phosphorus enrichment, complicating the assessment and management of eutrophication. This study analyses long-term time series of nutrients (total phosphorus (TP), dissolved inorganic phosphorus (DIP), dissolved inorganic nitrogen (DIN), and total nitrogen (TN)) and phytoplankton indicators (chlorophyll a and biomass) from contrasting Finnish coastal systems off Uusikaupunki and Rauma. Despite higher external phosphorus loading in Rauma, nutrient concentrations and phytoplankton biomass remain lower than in the semi-enclosed Uusikaupunki coastal zone. In contrast, Uusikaupunki exhibits higher chlorophyll a concentrations and lower TP:Chl a ratios, suggesting greater phosphorus bioavailability. At the offshore station SR5, TP and DIP increase below the surface layer, while surface concentrations show no significant trends, indicating phosphorus accumulation in deeper waters. Declining DIN:DIP ratios indicate a shift toward nitrogen limitation, under which primary production increasingly depends on phosphorus-supported nitrogen fixation. Chlorophyll a increases across the coastal gradient, including the outer archipelago, indicating a spatial expansion of eutrophication. Together, these findings are consistent with a system-level shift toward phosphorus-driven production. The results demonstrate a dual-control system in which basin-scale phosphorus enrichment determines long-term background conditions, while local nutrient loading and legacy effects regulate spatial variability in ecosystem response. More broadly, the findings highlight the importance of cross-scale interactions between regional nutrient enrichment and local ecosystem processes for understanding and managing eutrophication in inland and semi-enclosed marine systems. Full article

(This article belongs to the Section Marine Ecology)

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62 pages, 17228 KB

Open AccessArticle

Prediction-Driven Assessment of Multi-Ship Traffic Pressure and Maritime Traffic Situation

by Ruizhi Zhang, Qiang Li and Binjie Zhou

J. Mar. Sci. Eng. 2026, 14(13), 1233; https://doi.org/10.3390/jmse14131233 - 2 Jul 2026

Viewed by 309

Abstract

In increasingly complex navigation environments, maritime traffic supervision needs to look beyond the instantaneous collision risk of individual-ship pairs. A multi-ship scene may become difficult to monitor because of vessel aggregation, spatial compression, encounter urgency, and inconsistent motion states. To support proactive Vessel [...] Read more.

In increasingly complex navigation environments, maritime traffic supervision needs to look beyond the instantaneous collision risk of individual-ship pairs. A multi-ship scene may become difficult to monitor because of vessel aggregation, spatial compression, encounter urgency, and inconsistent motion states. To support proactive Vessel Traffic Services (VTS), this study proposes a prediction-driven framework for assessing multi-ship traffic pressure by combining AIS-based short-term motion prediction with a Spatio-Temporal Encounter Traffic Pressure Index (ST-TPI). In the proposed framework, cleaned and resampled AIS trajectories are used to train an LSTM model for short-term vessel motion prediction. The predicted vessel states are then synchronized into future multi-ship traffic snapshots over a 30 min horizon, and ST-TPI is used to evaluate traffic pressure at the ship-pair, individual-ship, regional, and scene levels. Different from conventional collision-risk or traffic-complexity methods, the proposed framework focuses on how future traffic pressure forms, changes, and is transferred among vessels and vessel pairs. The method was tested using five typical multi-ship scenarios and a real-waterway case in the western precautionary area of the Laotieshan Channel. The prediction results showed stable short-term forecasting performance with low meter-level position errors under the observation-updated rolling evaluation, providing a basis for future multi-ship snapshot generation. The typical scenarios revealed different pressure-evolution patterns, including low-pressure persistence, temporary compression and release, delayed crossing pressure, complex interaction release, and High-level pressure formation. The real-waterway case further showed low and Low-medium pressure fluctuations, local pressure peaks, pressure release, and pressure-source transfer under practical AIS conditions. Prediction-error perturbation analysis indicated that the main high-pressure vessel pairs and pressure-level interpretations remained stable under tested position perturbations. Consistency analysis further showed that ST-TPI scene pressure was significantly correlated with conventional CRI-based encounter-risk indicators. These results indicate that the proposed framework can provide interpretable information on future pressure-evolution and dominant pressure sources, supporting proactive monitoring, early warning, and traffic organization in complex waterways, and contributing to a safer maritime traffic environment. Full article

(This article belongs to the Section Ocean Engineering)

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21 pages, 7058 KB

Open AccessArticle

A Novel Cooperative Localization Algorithm Based on LSTM and Factor Graph for AUV Swarms

by Tong Sun, Weiming Xu, Yisong Deng and Jinyang Luo

J. Mar. Sci. Eng. 2026, 14(13), 1232; https://doi.org/10.3390/jmse14131232 - 2 Jul 2026

Viewed by 308

Abstract

To address localization error accumulation in autonomous underwater vehicle (AUV) swarms due to underwater acoustic communication interruptions, this paper proposes a cooperative localization method that integrates Long Short-Term Memory (LSTM) prediction and factor graph optimization. During the real-time stage, each AUV uses a [...] Read more.

To address localization error accumulation in autonomous underwater vehicle (AUV) swarms due to underwater acoustic communication interruptions, this paper proposes a cooperative localization method that integrates Long Short-Term Memory (LSTM) prediction and factor graph optimization. During the real-time stage, each AUV uses a trained LSTM to predict observations, ensuring the Unscented Kalman filter (UKF) maintains continuous state estimation during interruptions and mitigates error accumulation. During the post-processing stage, a factor graph comprising motion model factors, cooperative observation factors, and LSTM prediction factors is constructed on the AUV swarm master node. By adaptively switching factor types based on communication status, global nonlinear optimization is performed on the AUV states. Simulation results show that compared with UKF + LSTM, the proposed method reduces the Average Localization Error (ALE) by 55% and the Root Mean Square Error (RMSE) by 60%; compared with the Rauch–Tung–Striebel (RTS) smoothing algorithm, it reduces the ALE by 36% and the RMSE by 44%. This fully verifies that the strategy combining real-time state maintenance and post-processing global optimization can more effectively correct AUV localization errors in communication-interrupted regions. Experiments under different communication interruption durations further confirm the robustness of the proposed algorithm, with the maximum error-to-range ratio remaining below 0.2% of the range. Full article

(This article belongs to the Section Ocean Engineering)

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20 pages, 3391 KB

Open AccessArticle

Real-Time Physics-Based Accumulator Leakage Estimation for Hydraulic Integrity Monitoring of Subsea Blowout Preventer Systems with Signal-Based Consistency Analysis

by Sagar Gaur, Mohamed Amine Alouani, Chayma Guemri, Yingjie Tang, Matthew Franchek and Karolos Grigoriadis

J. Mar. Sci. Eng. 2026, 14(13), 1231; https://doi.org/10.3390/jmse14131231 - 2 Jul 2026

Viewed by 314

Abstract

Subsea blowout preventer (BOP) hydraulic control systems are safety-critical subsystems whose performance directly affects well control capability and emergency actuation reliability. Maintaining hydraulic integrity is essential because leakage-induced degradation can reduce stored actuation energy and compromise pressure delivery during critical operations. This paper [...] Read more.

Subsea blowout preventer (BOP) hydraulic control systems are safety-critical subsystems whose performance directly affects well control capability and emergency actuation reliability. Maintaining hydraulic integrity is essential because leakage-induced degradation can reduce stored actuation energy and compromise pressure delivery during critical operations. This paper presents a physics-based real-time monitoring methodology for accumulator leakage estimation in subsea BOP control systems using offshore pressure measurements. The approach estimates cycle-level leakage rates from hydraulic power unit pressure histories by analyzing pressure decay behavior during discharge cycles and applying recursive least-squares estimation (RLSE) for the adaptive tracking of leakage dynamics. To further assess whether the estimated leakage behavior reflects observable hydraulic system dynamics, a complementary signal-based consistency analysis is performed using features derived directly from the pressure measurements. The results indicate that the leakage states identified by the RLSE method correspond to statistically distinguishable and physically interpretable pressure patterns, supporting cross-method consistency. Because the methodology relies only on routinely available pressure measurements and requires no additional subsea instrumentation, the proposed framework provides a deployable approach for real-time hydraulic integrity monitoring and condition-based maintenance support. Full article

(This article belongs to the Special Issue Safety Analysis of Subsea Production System)

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20 pages, 8180 KB

Open AccessArticle

TrajE2E-MOT: Trajectory-Aware End-to-End Multi-Object Tracking in Maritime Radar

by Zhan Kong, Wei Xiong and Yaqi Cui

J. Mar. Sci. Eng. 2026, 14(13), 1230; https://doi.org/10.3390/jmse14131230 - 2 Jul 2026

Viewed by 281

Abstract

For autonomous maritime perception and situational awareness, the end-to-end multi-object tracking paradigm has achieved complete learning, from image sequences to tracking results, reducing the reliance on manually designed association rules and holding great potential. However, in maritime radar video multi-object tracking, due to [...] Read more.

For autonomous maritime perception and situational awareness, the end-to-end multi-object tracking paradigm has achieved complete learning, from image sequences to tracking results, reducing the reliance on manually designed association rules and holding great potential. However, in maritime radar video multi-object tracking, due to the limited visual features of targets and significant feature variations under long-term tracking, problems such as identity switching are prone to occur, making it difficult to directly apply existing end-to-end approaches. To solve these problems, this paper proposes a trajectory-aware end-to-end multi-object tracking method. The real-time trajectory of the targets contains temporal context information. This work uses it as prior knowledge to enhance visual feature encoding and compensate for the shortcomings of single-frame visual features. Specifically, the trajectory feature is encoded by the trajectory encoder module while, simultaneously, the visual features are encoded through the backbone and the visual feature encoder module. Then, in the frame-trajectory cross-modal attention module, the trajectory feature encoding is used to reconstruct the visual feature encoding with cross-attention, dynamically enhancing the features related to the target identity. Experiments on actual collected maritime radar video data show that the proposed method is effective, achieving improvements in several key indicators. Full article

(This article belongs to the Special Issue New Technologies in Autonomous Ship Navigation)

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25 pages, 12656 KB

Open AccessReview

Hydro-Mechanical Interfacial Behavior of Offshore Foundations Under Uplift Loading

by Maozhu Peng, Fuping Gao, Sen Mei and Jun Cheng

J. Mar. Sci. Eng. 2026, 14(13), 1229; https://doi.org/10.3390/jmse14131229 - 1 Jul 2026

Viewed by 576

Abstract

Anchoring systems for deep-water floating structures must withstand complex, hydro-mechanical (H-M) coupled uplift forces throughout an operational life extending over decades, yet fundamental understanding of this complicated H-M behavior remains insufficient. This paper presents a comprehensive review of H-M coupled foundation–seabed interactions under [...] Read more.

Anchoring systems for deep-water floating structures must withstand complex, hydro-mechanical (H-M) coupled uplift forces throughout an operational life extending over decades, yet fundamental understanding of this complicated H-M behavior remains insufficient. This paper presents a comprehensive review of H-M coupled foundation–seabed interactions under uplift loading. Key experimental findings are synthesized to demonstrate that the fundamental distinction between uplift and compression lies in the foundation-soil interface. Unique interfacial uplift behaviors are highlighted, including the progressive formation of an interfacial gap and the evolution of transient suction within it. This water-filled gap enables sustained tensile contact stress post-detachment, transforming traditional soil-structure interaction to the more general “soil–interfacial fluid–structure” interaction framework. A 1D conceptual model, representing a mechanistic extension of Terzaghi’s consolidation theory, is discussed to further elucidate these H-M mechanisms. For complex 3D numerical simulations, the limitations of traditional total-stress interface models are discussed, and specialized H-M thin-layer and zero-thickness interfaces designed for uplift modeling are critically examined regarding their advantages and limitations. The review concludes by outlining a roadmap for the next research frontier: high-fidelity treatments of sustained multidirectional cyclic loading, suction-induced liquefaction, and the long-term rheological evolution of the interface. Full article

(This article belongs to the Special Issue Wave–Structure–Seabed Interaction)

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19 pages, 2387 KB

Open AccessArticle

Robust Features, Adaptive Thresholds: LightGBM for Fishing Vessel Type Identification from Sparse AIS Data

by Shibo Li and Jianghua Sui

J. Mar. Sci. Eng. 2026, 14(13), 1228; https://doi.org/10.3390/jmse14131228 - 1 Jul 2026

Viewed by 226

Abstract

Under 10 min sparse Automatic Identification System (AIS) sampling, the reliability of point-wise motion statistics degrades substantially, and conventional classification methods rely on trajectory interpolation, which may introduce spurious motion patterns. This study proposes a feature-driven framework for fishing vessel type identification that [...] Read more.

Under 10 min sparse Automatic Identification System (AIS) sampling, the reliability of point-wise motion statistics degrades substantially, and conventional classification methods rely on trajectory interpolation, which may introduce spurious motion patterns. This study proposes a feature-driven framework for fishing vessel type identification that eliminates the need for interpolation preprocessing. A 39-dimensional feature set is constructed using robust statistics, including the median and interquartile range, to characterize trajectory-level behavioral patterns. Adaptive speed interval thresholds are derived through a data-driven approach grounded in Bayesian decision boundaries, thereby removing the dependence on manually defined cut-off values. A backward ablation procedure guided by feature importance ranking identifies a lightweight 12-dimensional feature subset that retains 98.7% of the classification accuracy at a compression rate of 69%. Evaluated on 18,320 fishing vessel trajectories in the East China Sea, the full 39-dimensional feature set achieves a 5-fold cross-validation accuracy of 91.92% (Macro-F1 = 0.919, Kappa = 0.879), with inter-fold standard deviations ranging from 0.002 to 0.004. Comparative experiments demonstrate that three tree-based classifiers all exceed 90% accuracy on the same feature set, confirming that feature robustness, rather than model selection, constitutes the dominant performance factor. LightGBM achieves the optimal trade-off between accuracy and training efficiency, whereas the cross-validation standard deviation of LSTM is approximately 7.5 times greater, indicating that hand-crafted robust features provide superior stability under sparse sampling conditions. The proposed framework requires no fishery-specific prior knowledge and offers a transferable paradigm for sparse AIS trajectory analysis. Full article

(This article belongs to the Section Ocean Engineering)

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19 pages, 63842 KB

Open AccessArticle

Carbonate Microfacies of the Coniacian–Santonian (Cretaceous) Deposits near the Kazerun Fault (Southwestern Iran): Evidence from Wells in a Divided Domain of the Zagros Basin

by Fatemeh Moradi-Doreh, Tahereh Habibi, Dmitry A. Ruban and Rohollah Hosseinzadeh

J. Mar. Sci. Eng. 2026, 14(13), 1227; https://doi.org/10.3390/jmse14131227 - 1 Jul 2026

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Abstract

Heterogeneities of Late Cretaceous tropical carbonate platforms of the Middle East are yet to be fully understood. The analysis of carbonate microfacies with materials obtained from exploration wells can contribute to filling the noted gap. The present study focuses on the Coniacian–Santonian deposits [...] Read more.

Heterogeneities of Late Cretaceous tropical carbonate platforms of the Middle East are yet to be fully understood. The analysis of carbonate microfacies with materials obtained from exploration wells can contribute to filling the noted gap. The present study focuses on the Coniacian–Santonian deposits near the Kazerun fault in the central part of the southern Zagros. The material from two exploration wells drilled east of this fault was used to establish carbonate microfacies and shale lithofacies and propose a depositional model. Six carbonate microfacies signify the existence of a homoclinal ramp, and inner-ramp environments were especially common. The stratigraphical distribution of the established microfacies made it possible to document a long-term transgression–regression cycle, which looks dissimilar to the global sea-level changes. Another control of this cycle might have been tectonic activity, particularly the activity of the Kazerun fault. The comparison of the lines of evidence from two wells east of this fault and two other wells west of this fault indicates striking differences. Full article

(This article belongs to the Section Geological Oceanography)

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J. Mar. Sci. Eng., Volume 14, Issue 13 (July-1 2026) – 111 articles

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