Journal of Marine Science and Engineering

20 pages, 1811 KiB

Open AccessArticle

Sentinel-2 Satellite-Derived Bathymetry with Data-Efficient Domain Adaptation

by Christos G. E. Anagnostopoulos, Vassilios Papaioannou, Konstantinos Vlachos, Anastasia Moumtzidou, Ilias Gialampoukidis, Stefanos Vrochidis and Ioannis Kompatsiaris

J. Mar. Sci. Eng. 2025, 13(7), 1374; https://doi.org/10.3390/jmse13071374 - 18 Jul 2025

Abstract

Satellite-derived bathymetry (SDB) enables the efficient mapping of shallow waters such as coastal zones but typically requires extensive local ground truth data to achieve high accuracy. This study evaluates the effectiveness of transfer learning in reducing this requirement while keeping estimation accuracy at [...] Read more.

Satellite-derived bathymetry (SDB) enables the efficient mapping of shallow waters such as coastal zones but typically requires extensive local ground truth data to achieve high accuracy. This study evaluates the effectiveness of transfer learning in reducing this requirement while keeping estimation accuracy at acceptable levels by adapting a deep learning model pretrained on data from Puck Lagoon (Poland) to a new coastal site in Agia Napa (Cyprus). Leveraging the open MagicBathyNet benchmark dataset and a lightweight U-Net architecture, three scenarios were studied and compared: direct inference to Cyprus, site-specific training in Cyprus, and fine-tuning from Poland to Cyprus with incrementally larger subsets of training data. Results demonstrate that fine-tuning with 15 samples reduces RMSE by over 50% relative to the direct inference baseline. In addition, the domain adaptation approach using 15 samples shows comparable performance to the site-specific model trained on all available data in Cyprus. Depth-stratified error analysis and paired statistical tests confirm that around 15 samples represent a practical lower bound for stable SDB, according to the MagicBathyNet benchmark. The findings of this work provide quantitative evidence on the effectiveness of deploying data-efficient SDB pipelines in settings of limited in situ surveys, as well as a practical lower bound for clear and shallow coastal waters. Full article

(This article belongs to the Section Physical Oceanography)

20 pages, 20226 KiB

Open AccessArticle

Characterization of the Internal and External Flow Field of a Semi-Submersible Aquaculture Platform with Multiple Net Cage Configuration

by Bo Hu, Jiawen Li, Juncheng Ruan, Jiawei Hao and Ji Huang

J. Mar. Sci. Eng. 2025, 13(7), 1373; https://doi.org/10.3390/jmse13071373 - 18 Jul 2025

Abstract

To achieve efficient and sustainable marine aquaculture, STAR-CCM+ was used to simulate the internal and external field characteristics of a semi-submersible aquaculture platform based on a porous media model, focusing on the influence of incoming flow velocity and net solidity ratio. The results [...] Read more.

To achieve efficient and sustainable marine aquaculture, STAR-CCM+ was used to simulate the internal and external field characteristics of a semi-submersible aquaculture platform based on a porous media model, focusing on the influence of incoming flow velocity and net solidity ratio. The results indicate that the flow field distribution around the platform exhibits no significant regularity and that low-velocity vortex regions are primarily concentrated near the pillars and nets. After velocity attenuation, the velocity reduction coefficients at the centers of the three cages are 90.26%, 63.65%, and 52.56%, respectively. Furthermore, the velocity attenuation inside the cages is minimally influenced by incoming flow velocity, with a maximum difference of 3.10%. In contrast, differences in net solidity ratio significantly affect velocity attenuation, particularly in downstream regions. The velocity reduction coefficient in the third cage varies by up to 43.25% depending on the net solidity ratio. These findings provide practical insights for the engineering design and application of aquaculture platforms. Full article

(This article belongs to the Section Coastal Engineering)

26 pages, 4382 KiB

Open AccessArticle

Effect of Biological Fouling on the Dynamic Responses of Integrated Foundation Structure of Floating Wind Turbine and Net Cage

by Yu Hu, Hao Liu, Yingyao Cheng, Jichao Lei and Junxin Liu

J. Mar. Sci. Eng. 2025, 13(7), 1372; https://doi.org/10.3390/jmse13071372 - 18 Jul 2025

Abstract

This paper proposes a novel integrated foundation structure of floating wind turbine and net cage by combining large capacity semi-submersible wind turbines with aquaculture cages. The research mainly focuses on the effect of biological fouling on net cage structures and safety performance of [...] Read more.

This paper proposes a novel integrated foundation structure of floating wind turbine and net cage by combining large capacity semi-submersible wind turbines with aquaculture cages. The research mainly focuses on the effect of biological fouling on net cage structures and safety performance of mooring systems. The study firstly validates the simplified model of net cage through comparing with results of existing scaled experimental models. Then, a hydrodynamic analysis is conducted on the net cage model to obtain the RAOs of motion response of the structure under frequency-domain analysis, and damping correction is also carried out on the structure. Finally, time-domain analyses under irregular wave conditions are conducted to evaluate the effects of biofouling fouling on motion responses of net cage foundation and tensions of mooring lines. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

33 pages, 6970 KiB

Open AccessArticle

Wake Characteristics and Thermal Properties of Underwater Vehicle Based on DDES Numerical Simulation

by Yu Lu, Jiacheng Cui, Bing Liu, Shuai Shi and Wu Shao

J. Mar. Sci. Eng. 2025, 13(7), 1371; https://doi.org/10.3390/jmse13071371 - 18 Jul 2025

Abstract

Investigating the coupled hydrodynamic and thermal wakes induced by underwater vehicles is vital for non-acoustic detection and environmental monitoring. Here, the standard SUBOFF model is simulated under eight operating conditions—speeds of 10, 15, and 20 kn; depths of 10, 20, and 30 m; [...] Read more.

Investigating the coupled hydrodynamic and thermal wakes induced by underwater vehicles is vital for non-acoustic detection and environmental monitoring. Here, the standard SUBOFF model is simulated under eight operating conditions—speeds of 10, 15, and 20 kn; depths of 10, 20, and 30 m; and both with and without thermal discharge—using Delayed Detached Eddy Simulation (DDES) coupled with the Volume of Fluid (VOF) method. Results indicate that, under heat emission conditions, higher speeds accelerate wake temperature decay, making the thermal wake difficult to detect downstream; without heat emission, turbulent mixing dominates the temperature field, and speed effects are minor. With increased speed, wake vorticity at a fixed location grows by about 30%, free-surface wave height rises from 0.05 to 0.15 m, and wavelength remains around 1.8 m, all positively correlated with speed. Dive depth is negatively correlated with wave height, decreasing from 0.15 to 0.04 m as depth increases from 5 to 20 m, while wavelength remains largely unchanged. At a 10 m submergence depth, the thermal wake is clearly detectable on the surface but becomes hard to detect beyond 20 m, indicating a pronounced depth effect on its visibility. These results not only confirm the positive correlation between vessel speed and wake vorticity reported in earlier studies but also extend those findings by providing the first quantitative evaluation of how submergence depth critically limits thermal wake visibility beyond 20 m. This research provides quantitative evaluations of wake characteristics under varying speeds, depths, and heat emissions, offering valuable insights for stealth navigation and detection technologies. Full article

(This article belongs to the Special Issue Advanced Studies in Ship Fluid Mechanics)

► Show Figures

Figure 1

18 pages, 9419 KiB

Open AccessArticle

STNet: Prediction of Underwater Sound Speed Profiles with an Advanced Semi-Transformer Neural Network

by Wei Huang, Junpeng Lu, Jiajun Lu, Yanan Wu, Hao Zhang and Tianhe Xu

J. Mar. Sci. Eng. 2025, 13(7), 1370; https://doi.org/10.3390/jmse13071370 - 18 Jul 2025

Abstract

The real-time acquisition of an accurate underwater sound velocity profile (SSP) is crucial for tracking the propagation trajectory of underwater acoustic signals, making it play a key role in ocean communication positioning. SSPs can be directly measured by instruments or inverted leveraging sound [...] Read more.

The real-time acquisition of an accurate underwater sound velocity profile (SSP) is crucial for tracking the propagation trajectory of underwater acoustic signals, making it play a key role in ocean communication positioning. SSPs can be directly measured by instruments or inverted leveraging sound field data. Although measurement techniques provide a good accuracy, they are constrained by limited spatial coverage and require a substantial time investment. The inversion method based on the real-time measurement of acoustic field data improves operational efficiency but loses the accuracy of SSP estimation and suffers from limited spatial applicability due to its stringent requirements for ocean observation infrastructures. To achieve accurate long-term ocean SSP estimation independent of real-time underwater data measurements, we propose a semi-transformer neural network (STNet) specifically designed for simulating sound velocity distribution patterns from the perspective of time series prediction. The proposed network architecture incorporates an optimized self-attention mechanism to effectively capture long-range temporal dependencies within historical sound velocity time-series data, facilitating an accurate estimation of current SSPs or prediction of future SSPs. Through the architectural optimization of the transformer framework and integration of a time encoding mechanism, STNet could effectively improve computational efficiency. For long-term forecasting (using the Pacific Ocean as a case study), STNet achieved an annual average RMSE of 0.5811 m/s, outperforming the best baseline model, H-LSTM, by 26%. In short-term forecasting for the South China Sea, STNet further reduced the RMSE to 0.1385 m/s, demonstrating a 51% improvement over H-LSTM. Comparative experimental results revealed that STNet outperformed state-of-the-art models in predictive accuracy and maintained good computational efficiency, demonstrating its potential for enabling accurate long-term full-depth ocean SSP forecasting. Full article

(This article belongs to the Special Issue Ocean Climate: Deep Learning, Statistical Methods and Dynamical Modeling)

► Show Figures

Figure 1

28 pages, 3717 KiB

Open AccessArticle

Comparison of Innovative Strategies for the Coverage Problem: Path Planning, Search Optimization, and Applications in Underwater Robotics

by Ahmed Ibrahim, Francisco F. C. Rego and Éric Busvelle

J. Mar. Sci. Eng. 2025, 13(7), 1369; https://doi.org/10.3390/jmse13071369 - 18 Jul 2025

Abstract

In many applications, including underwater robotics, the coverage problem requires an autonomous vehicle to systematically explore a defined area while minimizing redundancy and avoiding obstacles. This paper investigates coverage path-planning strategies to enhance the efficiency of underwater gliders particularly in maximizing the probability [...] Read more.

In many applications, including underwater robotics, the coverage problem requires an autonomous vehicle to systematically explore a defined area while minimizing redundancy and avoiding obstacles. This paper investigates coverage path-planning strategies to enhance the efficiency of underwater gliders particularly in maximizing the probability of detecting a radioactive source while ensuring safe navigation. We evaluate three path-planning approaches: the Traveling Salesman Problem (TSP), Minimum Spanning Tree (MST), and the Optimal Control Problem (OCP). Simulations were conducted in MATLAB R2020a, comparing processing time, uncovered areas, path length, and traversal time. Results indicate that the OCP is preferable when traversal time is constrained, although it incurs significantly higher computational costs. Conversely, MST-based approaches provide faster but fewer optimal solutions. These findings offer insights into selecting appropriate algorithms based on mission priorities, balancing efficiency and computational feasbility. Full article

(This article belongs to the Special Issue Innovations in Underwater Robotic Software Systems)

► Show Figures

Figure 1

19 pages, 14823 KiB

Open AccessArticle

Spatio-Temporal Variability in Coastal Sediment Texture in the Vicinity of Hydrotechnical Structures Along a Sandy Coast: Southeastern Baltic Sea (Lithuania)

by Donatas Pupienis, Aira Dubikaltienė, Dovilė Karlonienė, Gintautas Žilinskas and Darius Jarmalavičius

J. Mar. Sci. Eng. 2025, 13(7), 1368; https://doi.org/10.3390/jmse13071368 - 18 Jul 2025

Abstract

Hydrotechnical structures reshape sandy coasts by altering hydrodynamics and sediment transport, yet their long-term effects on sediment texture remain underexplored, particularly in the Baltic Sea. This study investigates the spatial and temporal variations in sediment grain size near two ports (Šventoji and Klaipėda) [...] Read more.

Hydrotechnical structures reshape sandy coasts by altering hydrodynamics and sediment transport, yet their long-term effects on sediment texture remain underexplored, particularly in the Baltic Sea. This study investigates the spatial and temporal variations in sediment grain size near two ports (Šventoji and Klaipėda) on the sandy Baltic Sea coast, considering the influence of jetties, nourishment, and geological framework. A total of 246 surface sand samples were collected from beach and foredune zones between 1993 and 2018. These samples were analyzed in relation to shoreline changes, hydrodynamic data, and geological context. The results show that sediment texture is most affected within 1–2 km downdrift and up to 4–5 km updrift of port structures. Downdrift areas tend to contain coarser, poorly sorted sediments because of erosion and the exposure of deeper strata, while updrift zones accumulate finer, well-sorted sands via longshore transport. In the long term, the geological framework controls sediment characteristics. In the medium term, introduced material that differs in grain size from natural beach sediments may alter the texture of the sediment, either coarsening or refining it. The latter slowly returns to its natural texture. Short-term changes are driven by storm events. These findings highlight the importance of integrating structural interventions, nourishment practices, and geological understanding for sustainable coastal management. Full article

(This article belongs to the Section Coastal Engineering)

► Show Figures

Figure 1

15 pages, 2932 KiB

Open AccessArticle

Optimization Study of the Line Array Layout of Slope–Pendulum Wave Energy Conversion Device

by Yue Zhao, Zhanhong Wan, Ze Li and Guiyu Cao

J. Mar. Sci. Eng. 2025, 13(7), 1367; https://doi.org/10.3390/jmse13071367 - 18 Jul 2025

Abstract

The development of wave energy is of great ecological and commercial value. This paper studies the linear vertical array arrangement of the slope–pendulum wave energy conversion device (S-PWEC). Based on the WEC-Sim open-source program, we build four wave energy-generating devices with linear vertical [...] Read more.

The development of wave energy is of great ecological and commercial value. This paper studies the linear vertical array arrangement of the slope–pendulum wave energy conversion device (S-PWEC). Based on the WEC-Sim open-source program, we build four wave energy-generating devices with linear vertical array distributions to study the power generation performance of the array platform and establish the factors influencing the array. S-PWEC is affected by radiation and a shading effect from neighboring devices in a linear vertical array configuration. The overall and individual power generation efficiencies are similar. An increase in the number of devices in the linear vertical array exacerbates the fluctuation of wave excitation moment and output power, indicating that there exists an optimal array configuration for maximizing the power generation efficiency. The performance of the array devices is significantly affected by the direction of incoming waves, and the spacing of the arrays should therefore be adjusted according to the periods of the sea state: increasing the spacing in small periods and decreasing the spacing in large periods can effectively improve the overall power generation. In the future, we will continue to study other array forms of S-PWEC to improve the conversion efficiency of array wave power generation devices. Full article

(This article belongs to the Special Issue Optimization and Energy Maximizing Control Systems for Wave Energy Converters—3rd Edition)

► Show Figures

Figure 1

19 pages, 9601 KiB

Open AccessArticle

Two-Hour Sea Level Oscillations in Halifax Harbour

by Dan Kelley, Clark Richards, Ruby Yee, Alex Hay, Knut Klingbeil, Phillip MacAulay and Ruth Musgrave

J. Mar. Sci. Eng. 2025, 13(7), 1366; https://doi.org/10.3390/jmse13071366 - 17 Jul 2025

Abstract

Halifax Harbour, a major seaport in Nova Scotia that is approximately 100 km southeast of the Bay of Fundy, comprises a deep inner region called Bedford Basin, connected to the adjacent ocean by a shallow channel called The Narrows. A study of sea [...] Read more.

Halifax Harbour, a major seaport in Nova Scotia that is approximately 100 km southeast of the Bay of Fundy, comprises a deep inner region called Bedford Basin, connected to the adjacent ocean by a shallow channel called The Narrows. A study of sea level and currents reveals the presence of episodic oscillations in The Narrows, with a period of approximately 2 h. The oscillation strength varies from day to day and, to some extent, through the seasons. The median amplitude of the associated sea level variation is

18 %

that of the de-tided signal, rising to

32 %

at the 95-th percentile. Values this large may be of concern for the transit of deep-draft vessels through shallow parts of the harbour and for the clearance of tall vessels under the two bridges that span The Narrows. Another concerning issue is the matter of oscillations being superimposed on storm surges. In addition to such direct effects of sea level variation, shear associated with the oscillations may increase the turbulent mixing in the region, affecting the overall state of this estuarine system. We explore the nature of the oscillations as a first step towards the improvement of prediction schemes for sea level and currents in the region. This involves an analysis of the oscillations in the context of seiche and Helmholtz resonance theories and the use of a 2D numerical model to handle realistic bathymetric conditions and other complications that the simpler theories cannot address. We conclude that the predictions of Helmholtz resonance theory are in reasonable agreement with both the observations and the predictions of the numerical model. Full article

(This article belongs to the Special Issue Marine Modelling and Environmental Statistics in Honor of Professor Keith Thompson)

► Show Figures

Figure 1

14 pages, 16969 KiB

Open AccessArticle

FTT: A Frequency-Aware Texture Matching Transformer for Digital Bathymetry Model Super-Resolution

by Peikun Xiao, Jianping Wu and Yingjie Wang

J. Mar. Sci. Eng. 2025, 13(7), 1365; https://doi.org/10.3390/jmse13071365 - 17 Jul 2025

Abstract

Deep learning has shown significant advantages over traditional spatial interpolation methods in single image super-resolution (SISR). Recently, many studies have applied super-resolution (SR) methods to generate high-resolution (HR) digital bathymetry models (DBMs), but substantial differences between DBM and natural images have been ignored, [...] Read more.

Deep learning has shown significant advantages over traditional spatial interpolation methods in single image super-resolution (SISR). Recently, many studies have applied super-resolution (SR) methods to generate high-resolution (HR) digital bathymetry models (DBMs), but substantial differences between DBM and natural images have been ignored, which leads to serious distortions and inaccuracies. Given the critical role of HR DBM in marine resource exploitation, economic development, and scientific innovation, we propose a frequency-aware texture matching transformer (FTT) for DBM SR, incorporating global terrain feature extraction (GTFE), high-frequency feature extraction (HFFE), and a terrain matching block (TMB). GTFE has the capability to perceive spatial heterogeneity and spatial locations, allowing it to accurately capture large-scale terrain features. HFFE can explicitly extract high-frequency priors beneficial for DBM SR and implicitly refine the representation of high-frequency information in the global terrain feature. TMB improves fidelity of generated HR DBM by generating position offsets to restore warped textures in deep features. Experimental results have demonstrated that the proposed FTT has superior performance in terms of elevation, slope, aspect, and fidelity of generated HR DBM. Notably, the root mean square error (RMSE) of elevation in steep terrain has been reduced by 4.89 m, which is a significant improvement in the accuracy and precision of the reconstruction. This research holds significant implications for improving the accuracy of DBM SR methods and the usefulness of HR bathymetry products for future marine research. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

21 pages, 2832 KiB

Open AccessArticle

A Crossover Adjustment Method Considering the Beam Incident Angle for a Multibeam Bathymetric Survey Based on USV Swarms

by Qiang Yuan, Weiming Xu, Shaohua Jin and Tong Sun

J. Mar. Sci. Eng. 2025, 13(7), 1364; https://doi.org/10.3390/jmse13071364 - 17 Jul 2025

Abstract

Multibeam echosounder systems (MBESs) are widely used in unmanned surface vehicle swarms (USVs) to perform various marine bathymetry surveys because of their excellent performance. To address the challenges of systematic error superposition and edge beam error propagation in multibeam bathymetry surveying, this study [...] Read more.

Multibeam echosounder systems (MBESs) are widely used in unmanned surface vehicle swarms (USVs) to perform various marine bathymetry surveys because of their excellent performance. To address the challenges of systematic error superposition and edge beam error propagation in multibeam bathymetry surveying, this study proposes a novel error adjustment method integrating crossover error density clustering and beam incident angle (BIA) compensation. Firstly, a bathymetry error detection model was developed based on adaptive Density-Based Spatial Clustering of Applications with Noise (DBSCAN). By optimizing the neighborhood radius and minimum sample threshold through analyzing sliding-window curvature, the method achieved the automatic identification of outliers, reducing crossover discrepancies from ±150 m to ±50 m in the deep sea at a depth of approximately 5000 m. Secondly, an asymmetric quadratic surface correction model was established by incorporating the BIA as a key parameter. A dynamic weight matrix ω = 1/(1 + 0.5θ²) was introduced to suppress edge beam errors, combined with Tikhonov regularization to resolve ill-posed matrix issues. Experimental validation in the Western Pacific demonstrated that the RMSE of crossover points decreased by about 30.4% and the MAE was reduced by 57.3%. The proposed method effectively corrects residual systematic errors while maintaining topographic authenticity, providing a reference for improving the quality of multibeam bathymetric data obtained via USVs and enhancing measurement efficiency. Full article

(This article belongs to the Special Issue Technical Applications and Latest Discoveries in Seafloor Mapping)

► Show Figures

Figure 1

24 pages, 2676 KiB

Open AccessReview

Biofouling on Offshore Wind Energy Structures: Characterization, Impacts, Mitigation Strategies, and Future Trends

by Poorya Poozesh, Felix Nieto, Pedro M. Fernández, Rosa Ríos and Vicente Díaz-Casás

J. Mar. Sci. Eng. 2025, 13(7), 1363; https://doi.org/10.3390/jmse13071363 - 17 Jul 2025

Abstract

Biofouling, the accumulation of marine organisms on submerged surfaces, presents a significant challenge to the design, performance, and maintenance of offshore wind turbines (OWTs). This work synthesizes current knowledge on the physical and operational impacts of biofouling on OWT marine substructures, with a [...] Read more.

Biofouling, the accumulation of marine organisms on submerged surfaces, presents a significant challenge to the design, performance, and maintenance of offshore wind turbines (OWTs). This work synthesizes current knowledge on the physical and operational impacts of biofouling on OWT marine substructures, with a particular focus on how it alters hydrodynamic loading, increases drag and mass, and affects fatigue and structural response. Drawing from experimental studies, computational modeling, and real-world observations, this paper highlights the critical need to integrate biofouling effects into design practices. Additionally, emerging mitigation strategies are explored, including advanced antifouling materials and AI-driven monitoring systems, which offer promising solutions for long-term biofouling management. By addressing both engineering and ecological perspectives, this paper underscores the importance of developing robust, adaptive approaches to biofouling that can support the durability, reliability, and environmental sustainability of the offshore wind industry. Full article

(This article belongs to the Section Marine Pollution)

► Show Figures

Figure 1

20 pages, 2811 KiB

Open AccessArticle

Investigation of Implantable Capsule Grouting Technology and Its Bearing Characteristics in Soft Soil Areas

by Xinran Li, Yuebao Deng, Wenxi Zheng and Rihong Zhang

J. Mar. Sci. Eng. 2025, 13(7), 1362; https://doi.org/10.3390/jmse13071362 - 17 Jul 2025

Abstract

The implantable capsule grouting pile is a novel pile foundation technology in which a capsule is affixed to the side of the implanted pile to facilitate grouting and achieve extrusion-based reinforcement. This technique is designed to improve the bearing capacity of implanted piles [...] Read more.

The implantable capsule grouting pile is a novel pile foundation technology in which a capsule is affixed to the side of the implanted pile to facilitate grouting and achieve extrusion-based reinforcement. This technique is designed to improve the bearing capacity of implanted piles in coastal areas with deep, soft soil. This study conducted model tests involving multiple grouting positions across different foundation types to refine the construction process and validate the enhancement of bearing capacity. Systematic measurements and quantitative analyses were performed to evaluate the earth pressure distribution around the pile, the resistance characteristics of the pile end, the evolution of side friction resistance, and the overall bearing performance. Special attention was given to variations in the lateral friction resistance adjustment coefficient under different working conditions. Furthermore, an actual case analysis was conducted based on typical soft soil geological conditions. The results indicated that the post-grouting process formed a dense soil ring through the expansion and extrusion of the capsule, resulting in increased soil strength around the pile due to increased lateral earth pressure. Compared to conventional piles, the grouted piles exhibited a synergistic improvement characterized by reduced pile end resistance, enhanced side friction resistance, and improved overall bearing capacity. The ultimate bearing capacity of model piles at different grouting depths across different foundation types increased by 6.8–22.3% compared with that of ordinary piles. In silty clay and clayey silt foundations, the adjustment coefficient η_s of lateral friction resistance of post-grouting piles ranged from 1.097 to 1.318 and increased with grouting depth. The findings contribute to the development of green pile foundation technology in coastal areas. Full article

(This article belongs to the Section Coastal Engineering)

► Show Figures

Figure 1

20 pages, 441 KiB

Open AccessArticle

Exploring the Impact of the Maritime Regulatory Framework on the Barrier System in Ship Operations

by Darijo Mišković and Huanxin Wang

J. Mar. Sci. Eng. 2025, 13(7), 1361; https://doi.org/10.3390/jmse13071361 - 17 Jul 2025

Abstract

The backbone of maritime transportation has always been the successful execution of ship operations. However, the human factor has proven to be a weak point in the system. To reduce and mitigate it, a regulatory framework and consequently a safety system for ship [...] Read more.

The backbone of maritime transportation has always been the successful execution of ship operations. However, the human factor has proven to be a weak point in the system. To reduce and mitigate it, a regulatory framework and consequently a safety system for ship barriers were created and implemented with this goal in mind. The expected result of these measures was the creation of a resilient maritime transport system. Nevertheless, the available statistics show that most of the reported accidents and incidents occurred during ship operation, with the human factor as the main cause. Therefore, it is useful to investigate whether the regulatory framework can influence the safety system of ship barriers. Therefore, the objectives of the study are as follows: (a) to investigate and determine the regulatory safety requirements and the elements related to the ship barrier system, and (b) to investigate the influence of the regulatory safety requirements on the elements related to the ship barrier system. From the data obtained and the analyses performed, seven factors emerged. Four of them were related to the regulatory requirements and three to the shipboard barrier system, a basis for the presented models. Several important findings were obtained that have theoretical and practical implications and further highlight the importance and potential undesirable side effects of the provisions of the current regulatory framework. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

13 pages, 1434 KiB

Open AccessArticle

Intra-Seasonal Acoustic Variation in Humpback Whale Songs in the North Colombian Pacific

by Juliana López-Marulanda and Hector Fabio Rivera-Gutierrez

J. Mar. Sci. Eng. 2025, 13(7), 1360; https://doi.org/10.3390/jmse13071360 - 17 Jul 2025

Abstract

Humpback whales (Megaptera novaeangliae) are well known for their complex acoustic communication, which plays a critical role in social interactions and reproduction. Understanding the variability in humpback whale songs is crucial to deciphering their communication strategies and the factors that influence [...] Read more.

Humpback whales (Megaptera novaeangliae) are well known for their complex acoustic communication, which plays a critical role in social interactions and reproduction. Understanding the variability in humpback whale songs is crucial to deciphering their communication strategies and the factors that influence these changes, which may affect reproductive success and population dynamics. While most studies of humpback whale song behavior have focused on annual variation, intra-seasonal changes remain underexplored. This study investigates intra-seasonal song variation in the Colombian Pacific humpback whale population, a unique and diverse breeding stock. We analyzed 37 h of recordings collected during two distinct periods of the 2019 breeding season (July and August–September) in the northern Colombian Pacific. Song repertoires were compared between periods, and the acoustic structure of a common song unit (Unit1) was analyzed using spectrographic cross-correlation. Results revealed a decrease in repertoire diversity over the course of the season, along with an increase in the song rate and the acoustic consistency of Unit1 during the second period. These findings highlight the dynamic nature of humpback whale song production and suggest potential influences of social learning and hormonal modulation. Such insights may be useful for the conservation and monitoring of humpback whale populations in breeding areas. Full article

(This article belongs to the Special Issue Recent Advances in Marine Bioacoustics)

► Show Figures

Figure 1

32 pages, 5641 KiB

Open AccessReview

Review of the Research on Underwater Explosion Ice-Breaking Technology

by Xiao Huang, Zi-Xian Zhong, Xiao Luo and Yuan-Dong Wang

J. Mar. Sci. Eng. 2025, 13(7), 1359; https://doi.org/10.3390/jmse13071359 - 17 Jul 2025

Abstract

Underwater explosion ice-breaking technology is critical for Arctic development and ice disaster prevention due to its high efficiency, yet it faces challenges in understanding the coupled dynamics of shock waves, pulsating bubbles, and heterogeneous ice fracture. This review synthesizes theoretical models, experimental studies, [...] Read more.

Underwater explosion ice-breaking technology is critical for Arctic development and ice disaster prevention due to its high efficiency, yet it faces challenges in understanding the coupled dynamics of shock waves, pulsating bubbles, and heterogeneous ice fracture. This review synthesizes theoretical models, experimental studies, and numerical simulations investigating damage mechanisms. Key findings establish that shock waves initiate brittle fracture via stress superposition while bubble pulsation drives crack propagation through pressure oscillation; optimal ice fragmentation depends critically on charge weight, standoff distance, and ice thickness. However, significant limitations persist in modeling sea ice heterogeneity, experimental replication of polar conditions, and computational efficiency. Future advancements require multiscale fluid–structure interaction models integrating brine migration effects, enhanced experimental diagnostics for transient processes, and optimized numerical algorithms to enable reliable predictions for engineering applications. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

17 pages, 4656 KiB

Open AccessArticle

Improved Super-Twisting Sliding Mode Control of a Brushless Doubly Fed Induction Generator for Standalone Ship Shaft Power Generation Systems

by Xueran Fei, Minghao Zhou, Yingyi Jiang, Longbin Jiang, Yi Liu and Yan Yan

J. Mar. Sci. Eng. 2025, 13(7), 1358; https://doi.org/10.3390/jmse13071358 - 17 Jul 2025

Abstract

This study proposes an improved super-twisting sliding mode (STSM) control method for a brushless doubly fed induction generator (BDFIG) used in standalone ship shaft power generation systems. Focusing on the problem of the low tracking accuracy of the power winding (PW) voltages caused [...] Read more.

This study proposes an improved super-twisting sliding mode (STSM) control method for a brushless doubly fed induction generator (BDFIG) used in standalone ship shaft power generation systems. Focusing on the problem of the low tracking accuracy of the power winding (PW) voltages caused by the parameter perturbation of BDFIG systems, a mismatched uncertain model of the BDFIG is constructed. Additionally, an improved STSM control method is proposed to address the power load variation and compensate for the mismatched uncertainty through virtual control technology. Based on the direct vector control of the control winding (CW), the proposed method ensured that the voltage amplitude error of the power winding could converge to the equilibrium point rather than the neighborhood. Finally, in the experimental investigation of the BDFIG-based ship shaft independent power system, the dynamic performance in the startup and power load changing conditions were analyzed. The experimental results show that the proposed improved STSM controller has a faster dynamic response and higher steady-state accuracy than the proportional integral control and the linear sliding mode control, with strong robustness to the mismatched uncertainties caused by parameter perturbations. Full article

(This article belongs to the Special Issue Control and Optimization of Ship Propulsion System)

► Show Figures

Figure 1

25 pages, 12171 KiB

Open AccessArticle

Multi-Strategy Fusion Path Planning Algorithm for Autonomous Surface Vessels with Dynamic Obstacles

by Yongshun Xie, Chengyong Liu, Yixiong He, Yong Ma and Kang Liu

J. Mar. Sci. Eng. 2025, 13(7), 1357; https://doi.org/10.3390/jmse13071357 - 17 Jul 2025

Abstract

Considering the complexity and variability inherent in maritime environments, path planning algorithms for navigation have consistently been a subject of intense research interest. Nonetheless, single-algorithm approaches often exhibit inherent limitations. Consequently, this study introduces a path planning algorithm for autonomous surface vessels (ASVs) [...] Read more.

Considering the complexity and variability inherent in maritime environments, path planning algorithms for navigation have consistently been a subject of intense research interest. Nonetheless, single-algorithm approaches often exhibit inherent limitations. Consequently, this study introduces a path planning algorithm for autonomous surface vessels (ASVs) that integrates an improved fast marching method (FMM) with the dynamic window approach (DWA) for underactuated ASVs. The enhanced FMM improves the overall optimality and safety of the determined path in comparison to the conventional approach. Concurrently, it effectively merges the local planning strengths of the DWA algorithm, addressing the safety re-planning needs of the global path when encountering dynamic obstacles, thus augmenting path tracking accuracy and navigational stability. The efficient hybrid algorithm yields notable improvements in the path planning success rate, obstacle avoidance efficacy, and path smoothness compared with the isolated employment of either FMM or DWA, demonstrating superiority and practical applicability in maritime scenarios. Through a comprehensive analysis of its control output, the proposed integrated algorithm accomplishes efficient obstacle avoidance via agile control of angular velocity while preserving navigational stability and achieves path optimization through consistent acceleration adjustments, thereby asserting its superiority and practical worth in challenging maritime environments. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

26 pages, 8299 KiB

Open AccessArticle

Experimental and Numerical Study on the Temperature Rise Characteristics of Multi-Layer Winding Non-Metallic Armored Optoelectronic Cable

by Shanying Lin, Xihong Kuang, Yujie Zhang, Gen Li, Wenhua Li and Weiwei Shen

J. Mar. Sci. Eng. 2025, 13(7), 1356; https://doi.org/10.3390/jmse13071356 - 16 Jul 2025

Abstract

The non-metallic armored optoelectronic cable (NAOC) serves as a critical component in deep-sea scientific winch systems. Due to its low density and excellent corrosion resistance, it has been widely adopted in marine exploration. However, as the operational water depth increases, the NAOC is [...] Read more.

The non-metallic armored optoelectronic cable (NAOC) serves as a critical component in deep-sea scientific winch systems. Due to its low density and excellent corrosion resistance, it has been widely adopted in marine exploration. However, as the operational water depth increases, the NAOC is subjected to multi-layer winding on the drum, resulting in a cumulative temperature rise that can severely impair insulation performance and compromise the safety of deep-sea operations. To address this issue, this paper conducts temperature rise experiments on NAOCs using a distributed temperature sensing test rig to investigate the effects of the number of winding layers and current amplitude on their temperature rise characteristics. Based on the experimental results, an electromagnetic thermal multi-physics field coupling simulation model is established to further examine the influence of these factors on the maximum operation time of the NAOC. Finally, a multi-variable predictive model for maximum operation time is developed, incorporating current amplitude, the number of winding layers, and ambient temperature, with a fitting accuracy of 97.92%. This research provides theoretical and technical support for ensuring the safety of deep-sea scientific operations and improving the reliability of deep-sea equipment. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

Journal Description

Journal of Marine Science and Engineering

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Further Information

Guidelines

MDPI Initiatives

Follow MDPI