This study addresses the growing environmental concerns of climate change, which is exacerbated by rising greenhouse gas emissions, particularly in the transportation sector. Maritime shipping, responsible for approximately 2.89% of global CO₂ emissions, is a key contributor to this issue. The International Maritime Organization (IMO) has set ambitious targets to reduce CO₂ emissions from this sector by 40% by 2030 and 100% by 2050, relative to 2008 levels. In response, this study explores the potential of combining two decarbonization strategies, slow steaming and wind-assisted propulsion systems (WAPS), to reduce emissions from maritime transport. The analysis of a 6500-ton DWT tanker operating around Sumatra Island, Indonesia, from July 21, 2023, to July 20, 2024, shows that slow steaming, reducing speed by up to 1 knot, can lead to up to a 20.1% reduction in fuel consumption and carbon emissions, although this results in increased sailing time. The challenge lies in balancing environmental benefits with operational time efficiency. The integration of WAPS, featuring three 250 m² square wingsails, further reduces emissions by 10.3% by harnessing wind power to assist propulsion, without altering the ship’s schedule. By combining both strategies, the tanker achieves a total emissions reduction of up to 29.7%, while maintaining operational efficiency. This combined approach offers a promising, sustainable solution for decarbonizing maritime transport and significantly reducing emissions without disrupting time-sensitive operations.

The exponential increase in plastic pollution, especially microplastics (MPs), is closely linked to human population growth, industrialization, and poor waste management practices. MPs have become a pervasive environmental contaminant, posing significant risks due to their ability to adsorb harmful substances and attached microorganisms. The Adriatic Sea is a critical region for studying microplastic pollution, ranking among Europe’s three most polluted seas, with plastic comprising 80% of waste. This study investigates the presence of MPs in three commercially important fish species - Gilthead seabream (Sparus aurata), Common pandora (Pagellus erythrinus), and Golden grey mullet (Chelon auratus) - collected from the northern Adriatic Sea. A total of 93 fish were analyzed, revealing that all extracted MPs were fibers, primarily black (42.4%) and blue (39.6%). The results indicate the higher MP contamination levels (80.64%) of S. aurata and C. auratus when compared to P. erythrinus (35.48%). This research contributes to a better understanding of microplastic pollution in the region and can improve the knowledge for effective monitoring and mitigation strategies. Future studies should focus on the long-term impacts of MPs on marine ecosystems and human health, particularly in commercially consumed species.

Within the framework of safeguarding Egypt’s coastal lowlands, which face escalating susceptibility to both climate change and human interventions, this study aims to provide a comprehensive analysis of sediment transport dynamics and their implications, with Damietta serving as a case study. To achieve this, a thorough review of the existing literature on sediment transport dynamics was conducted. MIKE21 Shoreline Morphology (MIKE21 SM) model was employed to simulate longshore sediment transport (LST) dynamics both before and after the construction of Damietta Port (DP). Analysis of the model output revealed that the model underestimated the influence of waves, primarily originating from the Northwest, on shaping the LST pattern. The results indicate that the construction of DP led to a reduction in average gross longshore sediment transport (GLST) and average net longshore sediment transport (NLST) by 18%, decreasing from 1.1 to 0.9 106 x m3/year, and 42%, decreasing from 0.73 to 0.42 x 106 m3/year, respectively. Additionally, the average monthly GLST and NLST reductions were 17% and 37%, respectively, compared to pre-construction conditions. Consequently, this research underscores the importance of continuous monitoring of sediment transport to ensure shoreline stability and protect surrounding ecological systems. This recommendation is vital for managing and mitigating the impacts of ongoing and future coastal interventions.

The article reveals the potential of using methanol as an ecologically clean fuel for ships today to solve the problem of reducing environmental pollution in the marine industry. The advantages of its use in the marine sector are given in comparison with other types of alternative fuels. Features of modernization of diesel engines for operation on methanol fuel are considered. It was established that by 2050, methanol is to occupy about 70% of the target global low-carbon fuel market. The main methods of methanol production are considered. A new methanol production technology was proposed, which involves the joint use of biomass and natural gas as raw materials. The advantage of the technology is that the heat obtained in the process of autothermal reforming during the conversion of natural gas can be used in making synthesis gas from biomass, which will increase the outcome of the finished product by 30% in total due to green methanol, a renewable fuel. New technological approaches and rational use of energy resources make it possible to reduce specific production costs and, under appropriate conditions, obtain methanol at a lower cost than that by carrying out each of the processes separately. The implementation of this technology will establish methanol as an economically efficient alternative fuel that causes less environmental damage and can effectively compete with traditional fuels in marine transport.

High-speed passenger vessels, integrated river and sea vessels, container vessels, oil tankers, and other underwater vehicles operating in maritime traffic are among the types of vessels that must be equipped with AIS and VHF. The safety of navigation is one of the major problems in the maritime sector, particularly in Vietnam. Furthermore, marine traffic in the seaport zone is a common and difficult issue to manage in areas with a high volume of vessel traffic, mostly in places where the infrastructure supporting navigation is inadequately developed to meet the rapidly growing demands of the contemporary world. Therefore, it is necessary to create an integrated maritime management system to improve the efficiency of data exploitation and support maritime safety. To address this challenge, this study suggests a Maritime Traffic State Prediction (MTSP) model to predict traffic conditions in the channels where real-time data collection is insufficient in some specific locations. We recommend a deep learning method using Long Short-Term Memory (LSTM) networks to predict the safe path of the vessel in case of missing data segments. The findings have shown that the proposed approach encourages the mining of historical vessel data for maritime traffic, is ready to be applied, and can easily be implemented in a computer program or a web-based app.

Long-term time series of wave parameters play a critical role in coastal structure design and maritime activities. At sites with limited buoy measurements, methods are used to extend the available time series data. To date, wave hindcasting research using machine learning methods has mainly focused on filling in missing buoy measurements or finding a mapping function between two nearshore buoy locations. This work aims to implement machine learning methods for hindcasting wave parameters using only publicly available Copernicus data. Ensemble regression and artificial neural networks were used as machine learning methods and the optimal hyperparameters were determined by the Bayesian optimization algorithm. As inputs, data from the MEDSEA reanalysis wave model were used for the wave parameters and data from the ERA5 atmospheric reanalysis model were used for the wind parameters. The results of this study show that the normalized RMSE of the test data improved by 29% for Rijeka and 12% for Split compared to the original MEDSEA wave hindcast at buoy locations. The proposed method was extremely efficient in removing bias in the original MEDSEA hindcasts (e.g., NBIAS = -0.35 for Rijeka) to negligible values for both Split and Rijeka (NBIAS < 0.03).

Power reduction is the central goal to maximize cruising duration of tourist underwater vehicles (UV) that can be achieved by shaping the hull. So, in this paper, hydrodynamic force of resistance of the tourist UV’s bare hull is analysed. A numerical model based on Computational Fluid Dynamics in OpenFOAM is developed to simulate the longitudinal movement of an UV in a viscous and incompressible fluid for the infinite water depth. Three head geometries, including both spherical heads (S-S), spherical bow and elliptical stern head (S-E), and UV with both elliptical heads (E-E) are compared. At the first step, the effects of the length-to-diameter ratio and forward speed is studied for the S-S UV. The mesh size is calibrated using Grid Convergence Index, provided by ASME, while the model validation is based on the results for cube and sphere as well as by comparison with resistance coefficient of a SUBOFF bare hull. S-E and E-E UVs are then analysed for typical length-to-diameter ratio, comparing their force of resistance to the S-S type. The elongated elliptical heads are in many cases found favourable compared to the spherical heads. The results of this study may be useful for the conceptual design of tourist UV and for verification of the complex numerical models that are necessary to account for the influence of appendages on the force of resistance of such innovative UV.

One of the most innovative developments in the field of advanced materials is sandwich materials. Sandwich material applications need standard requirements to be applied to marine structures, especially on ship construction. Sandwich material research is conducted on a laboratory scale to obtain the appropriate material composition in its development. In the process of developing this material, the material can be damaged. Most damage occurs in the core material, which results in difficulties in the identification process. This study compares damage identification methods based on free vibration analysis on the side sandwich plate of the ship’s hull. Damage-based identification is carried out to determine the response of vibration to the damage that occurs. Moreover, the method in this research uses a numerical approach and experimental vibration measurement. Numerical modelling is used to determine the appropriate boundary conditions and is shifted in experimental measurement. Damage modelling assumes that the material experiences core failure with a numerous variation model. Quantification of damage on the core correlates with natural frequency reduction due to a decrease in the stiffness of the sandwich material. Hence, the difference in the deviation value is used to determine the accuracy of damage identification.

The by-pass system of exhaust gas for the engine 6L20 Wartsila has been observed. The requirements of Annex VI MARPOL towards nitrogen oxide concentration in ship engine exhaust gases have been provided. The purpose of research was the determination of diesel 6L20 Wartsila by-pass exhaust gases optimum volume – at this the nitrogen oxide minimal concentration in exhaust gases is assured, the minimal increase (comparing with operation mode without by-pass) – specific effective fuel consumption, supporting of necessary thermal factor diapason of engine cylinders. The research was performed for the exhaust gas by-pass diapason 0…10 % with engine load diapason 0.55…0.85 % from nominal power. Upon experimental results it has been stated that the exhaust gas by-pass usage favors the ecological parameters of ships engine operation modes – by this at the range of exploitation load 0.55…0.85 % from nominal power the nitrogen oxide concentration in exhaust gas is decreased to 1.32….12.97 %. The exhaust gas by-pass impairs the combustion process and favors the increasing of specific effective fuel consumption and increasing the temperature of exhaust gases. The exhaust gas by-pass system effectiveness assessment should be performed by complex estimation of the following engine operation parameters: the nitrogen oxide concentration in exhaust gas, increasing of specific effective fuel consumption(SFOC), the exhaust gas temperature. As optimal degree of exhaust gas by-pass value when the maximum decrease of nitrogen oxide emission at minimal increase of fuel consumption and simultaneous engine thermal factor handling has to be considered.

Maritime English is an important factor in education of seafarers and acquisition of their highest powers and competencies. The aim of this research was to look into the attitudes of the students of Nautical Studies at the Maritime Departments of the University of Dubrovnik and the University of Zadar towards the importance of Maritime English with regard to their education and future profession. The study also included teachers at MET institutions in Dubrovnik, Zadar, Rijeka and Kotor. Two online questionnaires were created in Google forms and distributed during March/April 2021. The data were analysed by means of Fisher’s Exact Test and Spearman’s correlation. Both students and teachers set forth a positive attitude towards the importance of being fluent in English.