In response to the shortage of seafarers, which is a challenge for the coastal shipping industry, this report focuses on measures to increase the number of seafarers who become seafarers. In order to increase interest in seafaring as a career and maritime-related fields among young people, we have found that influencers who continuously influence them through maritime education play an important role. Opportunities should be sought to interact with young people while providing information on the maritime field (ships, seafarers, logistics, etc.). It was also found that there are a certain number of people who are interested in becoming seafarers even if they have no experience through maritime agents. At the same time, we found that lack of information about the reality of seafarers as a profession and the details of the qualification system is a factor that ultimately prevents them from finding employment. It is necessary to consider addressing this issue. In the future, the number of children will continue to decline, occupational choices will diversify, and in addition, job changes will become more standardized. In order to promote the stable recruitment of seafarers, measures and policies should be taken in line with these changing circumstances.

The Seto Inland Sea is one of the most congested areas in Japan, and supporting energy saving navigation in this sea is expected to have significant environmental impact reduction and economic benefits. However, due to these complex and special factors unique to the Seto Inland Sea, navigation support services utilizing weather routing have not become widespread. This study aims to develop a practical weather routing technique for ferries operating in the Seto Inland Sea area, based on forecasted tidal currents along the route with high spatio-temporal resolution, an estimation methodology that separates the passage time in the restricted area into variable and uncertain components, and a component-separated model that accurately estimates ship’s speed in actual sea based on collected data by capturing the characteristics of each area of the sea. Based on these methods, the authors developed a practical weather routing technique for planning energy-saving voyage, and quantitatively evaluated its effectiveness with observation data from actual vessels. In addition, the authors conducted pilot test in cooperated with shipping companies and crew members and confirmed the applicability, effectiveness, and appropriateness of the plan.

There are many mysterious phenomena in Toyama Bay, such as a wave with a period of 321 days, firefly squids surging over a coast at a new moon night in Spring and so on. We have continued to observe salinity, water temperature and tide levels in the Port of Fushiki-Toyama because there is a possibility that unknown mysterious phenomenon is found. Further, coastal currents and flow rates of river waters were investigated, too. The results are as follows.

(1)Salinity of coastal surface water in the Port of Fushiki-Toyama fluctuates periodically with periods of one day, about half month and about one month.

(2)The Periodic fluctuations are large in Spring and Autumn, but those are small in Winter and Summer.

(3)The quantities of five river waters in Toyama fluctuate significantly with 17 day period and almost the same phase.

The periodic fluctuations of salinity of the coastal surface water suggest that quantities of fresh waters, such as river waters and sea bottom spring waters supplied to the coastal water, fluctuate periodically. The quantities of river waters observed by Toyama Office of River and National Highway never fluctuate with a period of one day, therefore, there is a possibility that quantities of sea bottom spring waters fluctuate with one day period. Further, as a result of observing specific gravity of coastal surface water in the Port of Fushiki-Toyama, that of seawater less than one meter in depth is smaller than that of seawater from one meter to 7 meters in depth. It is a future problem to make the cause of periodic fluctuations of quantities of fresh waters supplied to the coastal water clear.

We proposed a system for the construction of a disaster network using three communication topologies based on Sub-GHz radios with radio base stations on shipboard for safety confirmation and evacuation information transmission to residents of islands in the Seto Inland Sea in the event of a large-scale disaster with a prolonged loss of power supply, and conducted a demonstration experiment using a prototype system. In this paper, we conducted a demonstration experiment of the Peer to Peer type for small settlements, in which a network was constructed and information was transmitted while moving the ship base station as a parent unit. The experiment was conducted based on a scenario assuming a disaster, and it was confirmed that information could be transmitted from the ship station to child stations on land and that damage information could be collected from the child stations to the ship station. This study has revealed that the network construction utilizing the characteristics of radio base station on ship and Sub-GHz radios can be useful in times of disaster in the islands of the Seto Inland Sea by appropriately adapting the three communication topologies to the target area.

This study was carried out focused on relationship between anchorage characteristic and classification sediments including moisture content (hereinafter referred to as "moisture content") in order to prevent marine accidents caused by dragging anchors under strong winds. Total 35 seabed sediments were collected at inside or nearby Nagasaki Port using a Smith-McIntyre Bottom sampler onboard the Kakuyo Maru, a training ship of the Faculty of Fisheries, Nagasaki University. The bottom sediment was classification based on the sediment symbol on the nautical chart, and one sample was extracted from each category to obtain the moisture content. Furthermore, the maximum holding force was measured using three types of model anchors: JIS type and Danforth type. As a result, the sediments were roughly divided into four groups and almost station was Si-fS based on the grain size composition of sediment. Moisture content was ranged from 21% to 47% and became larger around the quarantine anchorage area. The model anchor experiment showed that average holding coefficient of the Danforth anchor became more than 10 at St.1 and St.35, but JIS type anchor average holding coefficient was less than 4 at all stations even in regardless of the moisture content.

In May 2022 and May 2023, the methane hydrate plume generated from the seafloor at a depth of about 560 to 570 meters in the Joetsu Basin was investigated on the training cruise of Nagasaki University's fishery training vessel "Nagasaki-Maru". These observations have mainly been made with “the quantitative echo sounder”, also with “the multi-beam echo sounder”, “the sub-bottom profilers”, “the full-circle scanning sonar” and “the expandable conductivity, temperature and depth profiler”, which equipped at “Nagasaki-maru”. From these, we were able to confirm some plumes at a specific area that continued for over 10 years, and we were also able to estimate the surrounding seafloor shape, the subseafloor structure, which could estimate the presence of methane hydrate solid, and the water structure, which could prove the deflection and melting properties of the plumes.

In recent years there has got much interest in Ocean Surveillance, especially in the domain of Maritime Autonomous Surface Ships(MASS). Obstacle Detection System for MASS needs to detect automatically not only other ships but unspecified floating obstacles such as rubber boats or culturing rafts as well. The system consists of AIS, Radar and Camera-based Detection System as usual. The detection of obstacles through Camera Images mainly utilizes Detection Frameworks that use Deep-Learning Image Detection and Recognition Network Models such as YOLO. The Network Models are well-retrained by a large quantity of Sea photos with images of ships in the photos. However, each floating obstacle has various shapes that can’t be categorized properly. That makes it difficult to detect obstacles for the Network Model.

To address this problem, we have developed the Camera-based unspecified floating obstacles detection system which doesn’t need to learn the shapes of the obstacles. The program of the system consists of Feature Detection, Feature Matching, Clustering, and Object Tracking methods. The system stably detected and tracked floating obstacles each input size of which is over 50 pixels, and the rate of false detections keeps being low.

In this study, we investigated the risk cognition process for berthing maneuvers based on the comparison between experts (professional pilots) and novices (students in navigation course of Tokyo University of Marine Science and Technology). In the experiment, participants watched a video of a vessel entering or leaving port, rated the degree of risk at that moment, and listed the factors that evoke the risk as the degree of the risk changed. The responses were summarized and visualized using the evaluate grid method. The results showed that the risk cognition processes of the pilot and student were different from each other quantitatively. In the quantitative analysis, the pilot and student perceive risk at different moments, and while pilots judged risk based on whether they could control their situation, students did so based on their perception of the surrounding situation and did not predict the situation. The pilot's risk cognition, in terms of whether or not he is aware of specific accidents that could occur, changed qualitatively at risk levels of 3 and above. These results highlighted the expertise process from novice to expert.

The behavior of boat operators needs to ensure safe navigation. Operators are expected to be aware of hazards by conducting lookouts to understand their surroundings. Lookout is also described as an important behavior in training texts. It is difficult to know what to look out for at sea, and knowing what to look out for is necessary.

In this study, the gazing points of the operator during navigation around a port were measured with a gazing point measuring device, and a comparative analysis of the gazing points in divided sections was performed. The results also show that the gazing points of the pilots appeared in the expected hazardous areas around the port. However, there were many changes in the surroundings in a small area and there was variation in the movement of the gazing point.