Optimization of ship hull forms by changing CM and CB coefficients to obtain optimal seakeeping performance.

Ship design involves optimizing the hull in order to enhance safety, economic efficiency, and technical efficiency. Despite the long-term research on this problem and a number of significant conclusions, some of its content still needs to be improved. In this study, block and midship coefficients are incorporated to optimize the ship's hull. The considered ship was a patrol vessel. The seakeeping analysis was performed employing strip theory. The hull form was generated using a fuzzy model. Though the body lines generated by the midship coefficient (CM) and block coefficient (CB) varied indecently, the other geometric parameters remained the same. Multi-objective optimization was used to optimize CB and CM. According to the results of this study, these coefficients have a significant impact on the pitch motion of the patrol vessel as well as the motion sickness index. Heave and roll motions, as well as the added resistance, were not significantly influenced by the coefficients of CM and CB. However, increasing the hull form parameters increases the maximum Response Amplitude Operator (RAO) of heave and roll motions. The frequency of occurrence of the maximum roll RAO was in direct relation with CB and CM. These coefficients, however, had no meaningful impact on the occurrence frequency of other motion indices. In the end, the CB and CM coefficients were selected based on the vessel's seakeeping performance. These findings might be used by shipbuilders to construct the vessel with more efficient seakeeping performance.

Australia II: A Case Study in Engineering Ethics.

Australia II became the first foreign yacht to win the America's Cup in 1983. The boat had a revolutionary wing keel and a better underwater hull form. In official documents, Ben Lexcen is credited with the design. He is also listed as the sole inventor of the wing keel in a patent application submitted on February 5, 1982. However, as reported in New York Times, Sydney Morning Herald, and Professional Boatbuilder, the wing keel was in fact designed by engineer Peter van Oossanen at the Netherlands Ship Model Basin in Wageningen, assisted by Dr. Joop Slooff at the National Aerospace Laboratory in Amsterdam. Based on telexes, letters, drawings, and other documents preserved in his personal archive, this paper presents van Oossanen's account of how the revolutionary wing keel was designed. This is followed by an ethical analysis by Martin Peterson, in which he applies the American NSPE and Dutch KIVI codes of ethics to the information provided by van Oossanen. The NSPE and KIVI codes give conflicting advice about the case, and it is not obvious which document is most relevant. This impasse is resolved by applying a method of applied ethics in which similarity-based reasoning is extended to cases that are not fully similar. The key idea, presented in Peterson's book The Ethics of Technology (Peterson, The ethics of technology: A geometric analysis of five moral principles, Oxford University Press, 2017), is to use moral paradigm cases as reference points for constructing a "moral map".

Environmental DNA as a tool to reconstruct catch composition for longline fisheries vessels.

Global wild-capture fisheries are a large and diverse sector requiring various tools for fisheries-dependant data collection and effective Monitoring, Control and Surveillance (MCS). Here we present a novel protocol to collect eDNA from brine tanks onboard commercial longline vessels to reconstruct catch composition. We collected samples from nine vessels operating out of the Eastern Tuna Billfish Fishery, Australia, validating eDNA results with reliable catch data consisting of seven target and bycatch species. Environmental DNA was highly effective for detecting species retained on vessels without contamination or false positives. For four vessels, logbook data and eDNA were consistent with detections of all species. The remaining vessels detected all species except for rare catches of short-billed spearfish (Tetrapturus angustirostris). Similarities between rank abundance distributions of catch and eDNA reads were observed with logbook data mirrored when eDNA sequences were organised into rank order abundance. The method was effective at identifying highly abundant taxa retained in brine tanks- tuna (Thunnus spp.), swordfish (Xiphias gladius), marlin (Kajijia audax), and Atlantic Pomfret (Brama brama). Further research is required to validate how eDNA and other molecular monitoring tools can be scaled and applied to provide solutions for monitoring challenges in the fisheries sector.

Waste to resource recovery at a marina: Empirical evidence of upstream and downstream innovation for circularity.

In 2021, an Australian research centre partnered with a regional marina and shipyard where 90 businesses build, refit, and maintain boats in premium condition. Tenants and owners grapple with environmental waste management issues. Since there is a gap in applying action research but numerous calls to co-produce solutions and participate in translating ideas into practice, action research was used in this case study involving upstream and downstream innovation for circularity. Mixed methods data was collected through interviews, stakeholder workshops, and waste audits. A strategic action plan was created for closing the loop on waste. Interventions included tackling toxic, degradable products with natural alternatives, trading and remanufacturing materials to extend product life cycles, testing problematic materials, and pursuing product stewardship. This study is novel because it extends diffusion of innovation theory to real-world impact through a co-innovation process. Results underscore that ongoing achievements depend on properly sorting waste, accessing reprocessing facilities, and maintaining dedicated staff and partnerships, especially legislative support for making continuous improvement.

Anthropometric and physiological profiles of highly trained sailors in various positions and levels.

This study aimed to analyze anthropometric and physiological profiles of highly trained sailors and the differences between sailors regarding various training levels. Forty-two sailors (22 male, 22.4 ± 3.8 years; 20 females, 21.3 ± 3.6 years) were divided into helmsmen and crew groups, and the high- and low-level were distinguished. Sailors completed height, sitting height, legs length, weight, BMI, VO2max, 30 s all-out sprint, isometric mid-thigh pull (IMTP), countermovement jump, bench pull, core endurance tests. The results showed the crew had higher height, sitting height, weight, VO2max and lower trunk flexor endurance test times compared to the helmsmen (p < 0.05). The helmsmen had higher relative peak power/force in the 30 s all-out sprint and IMTP tests compared to the crew, whereas the crew had better absolute strength in bench pull, with significant differences between female sailors (p < 0.05). The high-level sailors showed more sailing experience than low-level sailors (p < 0.05). In conclusion, highly trained crew tend to be taller and heavier, while helmsmen have better trunk flexor endurance. For female sailors, helmsmen have better lower-body power and strength and crew have better upper-body strength. Sailing experience is a reliable variable to distinguish sailors' levels. The specific anthropometric and physiological profiles of sailors in various positions can assist sailing coaches in athlete selection and intervention training.

Maritime Freight Carbon Emission in the U.S. using AIS data from 2018 to 2022.

Global maritime emissions, a 3% contributor to greenhouse gases, anticipate a surge of 90-130% by 2050. Regulatory challenges persist due to international governance gaps. Legislative strides, including the EU Emission Trading System, highlight global efforts. In the U.S., despite legislative commitment, consensus hurdles impede cross-regional carbon management. Prevailing top-down emissions estimation methods warrant scrutiny. This paper unveils U.S. maritime emissions intricacies, focusing on carbon accounting, transfer, and compensation for cargo and tanker vessels. Leveraging AIS data (2018-2022), an activity-based/bottom-up approach navigates emissions calculations, aiming to reshape understanding and foster strategic reductions. The study bridges gaps in U.S. maritime emission research, promising insights into transfer and compensation dynamics. By concentrating on high-impact vessel types, it contributes to emissions mitigation strategies, steering towards a sustainable U.S. maritime future.

Forensic Geochemistry Reveals International Ship Dumping as a Source of New Oil Spill in Brazil's Coastline (Bahia) in Late 2023.

In the present study, we applied forensic geochemistry to investigate the origin and fate of spilled oils like tarballs stranded at the beaches of Bahia, in northeastern Brazil, in September 2023, based on their fingerprints. Saturated and aromatic compounds were assessed by gas chromatography, and the oceanic surface circulation patterns were deciphered to determine the geographic origin of the spill. Contamination by petroleum represents an enormous threat to the unique, species-rich ecosystems of the study area. The geochemical fingerprint of the oil spilled in 2023 did not correlate with those of previous events, including the one in 2019, the one in early 2022 in Ceará, and an extensive spill across the Brazilian Northeast in late 2022. However, the fingerprint did correlate with crude oils produced by Middle Eastern countries, most likely Kuwait. The oil of the 2023 spill had a carbonate marine origin from early mature source rocks. These findings, together with the moderate weathering of the 2023 tarballs and the ocean circulation patterns at the time of the event, indicate that the oil was discharged close to the shore of Brazil, to the east or southeast of Salvador, by a tanker on an international route in the South Atlantic.

The Mediating Effect of Well-Being, Happiness, and Trust in the Relationship Between Work-Life Balance and Work Effectiveness in Seafarers.

In the contemporary global context, seafarers persist as the uncelebrated heroes of international trade, despite their substantial contributions. The current estimate places the number of STCW- certified officers at 857 540, reflecting a notable increase of 10.8% since 2015. Nevertheless, there is a growing recognition of the imperative to accord specific attention to seafarers' mental and physical well-being. During their tenures aboard ships, seafarers confront various challenges, including psychological well-being, work-life imbalance, dissatisfaction, diminished performance, and a sense of mistrust toward the organizational framework. The primary objective of this research is to scrutinize the nexus between work-life balance and work effectiveness, exploring the mediating roles of psychological well-being, organizational happiness, and organizational trust. A questionnaire-based survey is meticulously crafted to achieve this, employing a dataset comprising 420 seafarers engaged in diverse vessel types in Turkey, operating under both Turkish and international flags. Methodologically, structural equation modeling and correlation analyses are executed to assess the formulated research hypotheses rigorously. The empirical findings of this research reveal noteworthy mediating roles: psychological well-being exhibits a complete mediation effect, organizational happiness demonstrates a full mediation effect, and organizational trust manifests a partial mediation effect. These outcomes underscore the nuanced interplay between work-life balance and work effectiveness in the seafaring context. The implications of these findings extend significantly to the maritime sector and industry, accentuating the imperative for targeted interventions to enhance the well-being and performance of seafaring professionals.

Exploring perspectives and insights of experienced voyagers on human health and Polynesian oceanic voyaging: A qualitative study.

BACKGROUND: The Worldwide Voyage (WWV) was a 3-year (2014-2017) open-ocean voyage to circumnavigate the world using Indigenous knowledge and navigational skills aboard Hokule'a, a traditionally designed Native Hawaiian (NH) voyaging canoe (wa'a kaulua). Each WWV segment included experienced crew and leadership who were recognized by their voyaging peers as highly experienced in Polynesian oceanic voyaging. This study explored the perceptions and insights of WWV-experienced ocean voyagers on the interconnection between human health and oceanic voyaging. METHODOLOGY: A constructivist approach with a storytelling-based moderator guide was used to conduct focus groups and informant interviews of experienced crew and voyaging leadership. Participants were interviewed and recorded transcripts were analyzed using content analysis. Triangulation of analysis included secondary thematic review by two independent NH cultural practitioners and participant member checking. Purposive sampling was used to enroll 34 of 66 eligible highly experienced voyagers (leadership n = 6; crew n = 28) in 5 focus groups and 4 informant interviews. RESULTS: Six themes emerged: 1) Indigenous context (spiritual and natural environment); 2) Importance of relationships and community; 3) Description of life on the canoe; 4) Holistic health; 5) Mindfulness, stress reduction and emotional health; and 6) Opportunities for intervention. Themes 1-5 were inductive and intricately interrelated, and theme 6 was deductive in that it directly resulted from a moderator guide question. Theme 6 offers strategies to improve the impact of voyaging and health well beyond the physical voyage with recommendations for improved transition back to land and developing a wa'a community context, which reflects a traditional voyaging experience. CONCLUSIONS: Polynesian oceanic voyaging is strongly perceived as a positive and transformative holistic-health-promoting experience. SIGNIFICANCE: Recommendations to promote generalizable health benefits of a voyaging lifestyle offers a promising and culturally grounded approach warranting future studies to understand mechanism and potential impact for improving health inequities.

Interventional Study of Nonpharmaceutical Measures to Prevent COVID-19 Aboard Cruise Ships.

Cruise ships carrying COVID-19-vaccinated populations applied near-identical nonpharmaceutical measures during July-November 2021; passenger masking was not applied on 2 ships. Infection risk for masked passengers was 14.58 times lower than for unmasked passengers and 19.61 times lower than in the community. Unmasked passengers' risk was slightly lower than community risk.

Regulating seafarers' welfare: an examination of the protection of Filipino seafarers' well-being through a legal analysis of the POEA-Standard Employment Contract.

BACKGROUND: The Philippines is the global maritime industry's single biggest source of seafarers. This article examines how the Philippines protects the welfare of its seafarers working on board ocean-going vessels. MATERIALS AND METHODS: We employed a multi-method approach to better understand the POEA-SEC as a regulatory instrument. First, we analysed Philippine legislation and regulations that are shaping the employment, welfare, and working conditions of Filipino seafarers. Second, we examined the Philippine Overseas Employment Administration Standard Employment Contract (POEA-SEC) which requires that minimum standards of employment for seafarers are met. We use legal analysis to examine three specific provisions that pertain to their well-being: duration of employment, monetary considerations, and working conditions in terms of hours of work and rest periods. Third, we analysed interview and focus group data on the experiences of Filipino seafarers on board ships in respect of the POEA-SEC's efficacy in protecting their well-being. RESULTS: Analysis of the policy environment for Filipino seafarers shows how the interests of powerful actors have taken precedence over those of Filipino seafarers. Seafarers' experiences suggest that they cannot be reached by the contract, whether symbolic or otherwise. The contract fails to address seafarer issues, such as security of tenure, excessive working hours resulting in fatigue, stress and anxiety. CONCLUSIONS: The POEA-SEC falls short as a legal document to address occupational, health and safety issues, which contribute to the detriment of seafarers' health and well-being. This indicates that the Philippine government cannot fully protect its seafarers.

Self-reported diabetes mellitus among seafarers: occupational and sociodemographic predictors.

BACKGROUND: Seafarers are at increased risk of diabetes due to their lifestyle and working conditions on board ships. There is, however, limited evidence regarding the magnitude of diabetes and its risk factors. In this study, we aimed to assess the prevalence of self-reported diabetes among seafarers on board ships and identify risk factors associated with it. MATERIALS AND METHODS: A cross-sectional epidemiological survey was conducted among seafarers aboard ships between November and December 2022. The study enrolled a total of 4,500 seafarers aged 18 and older. Data were collected using anonymous, standardized questionnaires. The association between the outcome variable and the independent variables was assessed using binary logistic regression models. RESULTS: In total, 2,986 participants were included in the study. The prevalence of self-reported diabetes among seafarers was found to be 8.2% (95% CI: 7.2-9.2). Self-reported diabetes prevalence among officers and non-officers was 7% and 9%, respectively. The mean age of study participants was 37.96 ± 10.22, while the mean age of participants with diabetes was 47.5 ± 9.46. Independent predictors of self-reported diabetes mellitus were age (51+ years) [adjusted odds ratio (AOR): 3.52, 95% confidence interval (CI): 1.46-8.95], rank (non-officer) [AOR: 1.65; 95% CI: 1.14-2.40], worksites (engine) (AOR: 2.08, 95% CI: 1.19-3.77), work experience (10-20 years) (AOR: 4.66, 95% CI: 2.33-10.05), work experience (21+ years) (AOR: 5.01, 95% CI: 2.32-11.55), working hours per week (57-70 hours) (AOR: 1.57, 95% CI: 1.08-2.31), working hours per week (71+ hours) (AOR: 1.80, 95% CI: 1.17-2.80), self-reported hypertension (AOR: 1.44, 95% CI: 1.03-1.99), overweight (AOR: 1.74; 95% CI: 1.24-2.47), and obesity (AOR: 2.93; 95% CI: 1.84-4.65). CONCLUSIONS: This study revealed that one in twelve seafarers between the ages of 19 and 70 have self-reported diabetes. The present study identified significant risk factors associated with diabetes. Risk factor mitigation strategies aimed at high-risk groups should be implemented on board ships.

Exposure to hull cleaning wastewater induces mortality through oxidative stress and cholinergic disturbance in the marine polychaete Perinereis aibuhitensis.

While wastewater and paint particles discharged from the in-water cleaning process of ship hulls are consistently released into benthic ecosystems, their hazardous effects on non-target animals remain largely unclear. In this study, we provide evidence on acute harmful effects of hull cleaning wastewater in marine polychaete Perinereis aibuhitensis by analyzing physiological and biochemical parameters such as survival, burrowing activity, and oxidative status. Raw wastewater samples were collected during ship hull cleaning processes in the field. Two wastewater samples for the exposure experiment were prepared in the laboratory: 1) mechanically filtered in the in-water cleaning system (MF) and 2) additionally filtered with a 0.45 µm filter in the laboratory (LF). These wastewater samples contained high concentrations of metals (zinc and copper) and metal-based booster biocides (copper pyrithione and zinc pyrithione) compared to those analyzed in seawater. Polycheates were exposed to different concentrations of the two wastewater samples for 96 h. Higher mortality was observed in response to MF compared to LF-exposed polychaetes. Both wastewater samples dose-dependently decreased burrowing activity and AChE activity. Drastic oxidative stress was observed in response to the two wastewater samples. MDA levels were significantly increased by MF and LF samples. Significant GSH depletion was observed with MF exposure, while increased and decreased GSH contents were observed in LF-exposed polychaetes. Enzymatic activities of antioxidant components, catalase, superoxide dismutase, and glutathione S-transferase were significantly modulated by both wastewater samples. These results indicate that even filtered hull cleaning wastewater can have deleterious effects on the health status of polychaetes.

Not so silent spectators: How spectator vessels at international sailing regattas alter marine soundscapes.

International sailing regattas are major sporting events often held within coastal marine environments which overlap with the habitats of marine species. Although races are confined to courses, the popularity of these events can attract large spectator flotillas, sometimes composed of hundreds of motorized vessels. Underwater noise from these flotillas can potentially alter soundscapes experienced by marine species. To understand how these flotillas may alter soundscapes, acoustic recordings were taken around racecourses during the 36th America's Cup in the Hauraki Gulf, New Zealand in 2021. Sustained increases in broadband underwater sound levels during the regatta (up to 17 dB re 1 µPa rms; 0.01-24 kHz) that extended beyond racecourse boundaries (>8.5 km) and racing hours were observed; very likely attributable to the increase in regatta-related vessel activity. Underwater noise pollution from spectator flotillas attending larger regattas should be considered during event planning stages, particularly when events occur in ecologically significance areas.

Analysis of emission characteristics associated with vessel activities states in port waters.

This study investigates AIS data from March 2019 to February 2020 in Shanghai Port waters. The ship activities of berthing, waiting, and ingress/egress are extracted in detail to elucidate the emission characteristics of ships in Shanghai Port, differentiating emissions patterns across various ship activity. The findings reveal that the top three pollutants within Shanghai Port are CO2, NOX, and SO2. Container ships have the highest emissions, followed by bulk carriers. Berthed container ships and oil tankers exhibit the highest emission. Waiting container ships emit the most, followed by oil tankers and bulk carriers. Among ships entering and leaving the port, low-speed navigation produces the most emissions, followed by maneuvering and steady-speed navigation. Emission hotspots include the Yangtze River Estuary Anchorage and the main navigation channel into and out of the port. This study offers robust data support for an in-depth understanding and evaluation of ship emission characteristics in Shanghai Port.

Smart regulations in maritime governance: Efficacy, gaps, and stakeholder perspectives.

The paper explores maritime environmental regulations, analyzing industry perspectives and their operational execution. It critically assesses the International Maritime Organization (IMO) regulations' effectiveness in mitigating climate challenges within the shipping domain. The central argument is that the evolving and intricate nature of maritime regulations often impedes policy goal realization, enforcement, impact evaluation, and equity perception. Utilizing both quantitative and qualitative methodologies, this research gathers, analyses, and interprets data via surveys and interviews. This exploration seeks to evaluate the regulations' impact on reducing shipping's negative impact, especially concerning emissions, waste management, and noise pollution, under the umbrella of smart regulations. The results indicate that the current regulatory approach is neither comprehensive nor immediate, necessitating a more agile, digitally enabled framework to adapt to fast-changing industry conditions.

Comparing pre-industrial and modern ocean noise levels in the Santa Barbara Channel.

To understand the extent of anthropogenic noise in the ocean, it is essential to compare the differences between modern noise environments and their pre-industrial equivalents. The Santa Barbara Channel, off the coast of Southern California, is a corridor for the transportation of goods to and from the busiest shipping ports in the Western hemisphere. Commercial ships introduce high levels of underwater noise into the marine environment. To quantify the extent of noise in the region, we modeled pre-industrial ocean noise levels, driven by wind, and modern ocean noise levels, resulting from the presence of both ships and wind. By comparing pre-industrial and modern underwater noise levels, the low-frequency (50 Hz) acoustic environment was found to be degraded by more than 15 dB. These results can be used to identify regions for noise reduction efforts, as well as to model scenarios to identify those with the greatest potential to support marine conservation efforts.

A life cycle cost analysis of different shore power incentive policies on both shore and ship sides based on system dynamics and a Chinese port case.

Shore power (SP) is widely recognized as an efficient strategy for reducing air pollution in port areas. Unfortunately, the adoption of SP has been relatively low, resulting in limited emission reductions and financial losses. To address these challenges, this paper focuses on enhancing the utilization rate of SP, which is meaningful for emission control and environmental protection. This paper combines system dynamics with a study of the benefits of SP, which bridges the research gap to some extent. We propose a system dynamics model that assesses the impact of various incentive policies on the economic and environmental benefits of SP. The model considers the life cycle cost and comprises four subsystems. By conducting a case study on Nansha Port, we find that price subsidies are more effective than construction subsidies in overcoming economic barriers. Furthermore, we observe that the overall economic benefits only increase when the electricity price decreases. This is because lowering the electricity price enhances the profitability of ships without negatively affecting port revenue. Additionally, it is the proportion of the electricity price and service price that determines the overall economic benefits, rather than the SP price itself. Hence, it is recommended to provide preferential subsidies for the electricity price.

Reduction of the harmful NOx pollutants emitted from the ship engines using high-pressure selective catalytic reduction system.

Various techniques are used to reduce harmful pollutants such as NOX emissions from ships. Selective catalyst reduction (SCR) systems are the most effective technique used to reduce NOX emissions. In this study, the effects of an SCR reactor on NOX emissions and performance in high-pressure selective catalytic reduction (HP-SCR) systems were investigated numerically. In numerical studies, the effects of SCR system diameter, output form, catalyst activation energy, mixing zone length, and location were investigated as parametric, and the most suitable system geometry was determined. The effects of geometric parameters and catalyst type on emission and performance such as NOX reduction, NH3 slip, velocity, and pressure loss were investigated. It was determined that with increasing system diameter, whereas the NOX reduction performance increased depending on exhaust velocity, the pressure drop decreased, and the most suitable system diameter was determined as 780 mm. Furthermore, the obtained results showed that the performance of NOX reduction decreased after 2 × 106 kJ/kmol activation energy, and the most suitable SCR output form was conical geometry. In terms of the environment, this study will contribute to achieving the UN Sustainable Development Goals such as climate action (SDG 13).