Accurate passenger location information can be obtained through the ship environment-aware indoor positioning algorithm. It is possible to determine whether the physical distance between passengers is maintained with location information. If the ship passenger does not maintain a physical distance, a warning message will be sent to the passenger’s mobile phone to observe the specified distance (Figure 1) ^[1]. Furthermore, it is judged that it may be recommended to disinfect the area by comparing the passenger location. The denser people are, the higher the risk of virus transmission. Therefore, extracting the area of stay or identifying the dangerous area can disinfect potential virus transmission areas early, reducing the risk of virus transmission. The crew identifies the passenger location information and inspects compliance with quarantine. Therefore, high precision ship indoor location tracking technology and potential viral propagation risk calculation are fundamental in early quarantine measures.

Considering the long-term stay of passengers and flight attendants, the maximum number of passengers available should be evaluated so that all necessary measures can be effectively implemented and the number can be reviewed regularly. In principle, the same level of protection should be provided to all passengers, regardless of the presence or absence of passengers, crew, or visitors. The number of passengers can be easily calculated, and trajectory information can be obtained through onboard positioning technology, allowing careful management of passengers. The onboard location identification technology can differentiate location information for each person and grade the number of persons on board by acquiring all location information for the number of persons on board. Since the number of persons on board is different, independent authority is often required in essential areas of the ship. The measures proposed in this study plan can be flexibly changed according to various application environments. For example, the following is about consumable items to be considered when including ship operation in the plan.

Consumption of personal protective equipment (PPE) may vary for each type. For example, if the number of persons onboard is only indoors, PPE is likely to be used in duplicate. PPE may be consumed more by staff or passengers who frequently work in dense areas. This is because recycling PPE is low due to many contacts. OD data extraction technology shows that the occupant has stayed or moved. Mathematical relations with PPE consumption can predict future PPE consumption, a valuable reference for shipbuilders to plan for PPE stockpiles. Similarly, it is possible to establish a mathematical relationship between occupant movement activity and disinfectant consumption. Waste incineration can be predicted through algorithms, and disinfection equipment can be prepared in advance.

Ships can dynamically set sensory, physical distances for different onboard areas. For example, the ship engine room has a physical distance that is too small to meet quarantine regulations, so the actual physical distance for each area can be calculated considering the size of the ship space and the actual physical distance set by the number of persons on board. An electronic fence can be set up with an electronic fence through the location information of asymptomatic people. Notice can also be sent to protect the public hygiene of other passengers by guiding them to stay away from when entering closed spaces and areas with a high risk of transmission.

It is recommended that the company review where the relevant information should be provided from shipboard to disembarkation. The way information is delivered should also be reviewed and digital as much as possible. The information should include aspects related to the adopted preventive measures, the health examination process being implemented, and the protocol related to repatriation and disembarkation in the event of a disease. For example, the information to be displayed for each boarding space for the required physical distance, maximum capacity, and PPE should also be considered. The information provided should also include measures applied when visiting the community. All data may be displayed based on location information. It is to digitize the activities of onboard personnel based on location information. It can also function as a healthy constitution through the location information of the number of persons on board. For example, close contacts can be found and quarantined according to the comparison results with location information of COVID-19 patients. Ship passengers ensure that physical distance is maintained and overcrowding is prevented or reduced.

In this respect, it is vital to maintain consistency of physical distance recommendations in various areas of the ship. Floor markings representing the recommended physical distance can help keep it from passengers. If the crew interacts with a passenger in a fixed position, the protective barrier may be considered to facilitate safe interaction. If possible, removing or rearranging furniture items can reduce overcrowding. Companies should consider whether the maximum personnel capacity should be reviewed so that the physical distance applicable to each space or space category and the entire ship can be maintained. If the port and the boat use different standards, it is recommended to agree on a single distance between the port and the boat. When physical distance cannot be guaranteed, it is recommended to use a face mask as a source control means to reduce diffusion.

Based on the location information of the number of persons on board, it is possible to calculate in real-time whether the physical distance between them can meet the quarantine needs. If the requirements are not met, caution, such as sending information, can be called to maintain the physical distance of the quarantine request. In addition, when the location information of the number of persons on board is known, crowded areas can be determined or predicted through algorithms, and excessive congestion can be avoided by inducing them to move to their destinations through crowds or recommending other destinations. This reduces the management stress of practitioners and lowers the risk of virus transmission. Combining the location information of the number of persons on board with the value of the ship space capacity can calculate the maximum number of persons onboard based on the current capacity of the ship and the physical distance of quarantine regulations. Using the results of this study can help shipping companies make ticket plans.

Frequent and careful hand hygiene using water and soap or alcohol-based disinfectant solutions can mitigate the risk of COVID-19. It should be easy to access health promotion materials that promote the importance of handwashing facilities, alcohol-based hand rubbing solutions, and hand hygiene and explain effective hand hygiene practices. The plan should include the availability of alcohol-based hand sanitizers in spaces expected to have people, such as restaurants, elevators, corridors, sanitary spaces, workplaces, and changing rooms in general entrance security inspection areas. Onboard positioning equipment, such as beacons, can be installed where hand washing and alcohol disinfectants are present. The passenger location information, location of the sink, and the time spent nearby can be used to calculate the number of times the crew cleaned their hands. By establishing a health database, it is possible to increase efficiency by paying attention to persons on board with a small number of clean lines and guiding them to wash their hands immediately to comply with quarantine regulations or disinfect them. In addition, the health examination protocol should be non-discriminatory. This research task technology provides basic location information of the number of persons on board, and a health check system can be established using it. If the distance between persons on board is compared and the area is entered and departed, the health of persons on board can be checked.

Before starting the voyage, the cruise ship operator must have a call route along the route and ensure that passengers and flight attendants can receive medical treatment if necessary. Repatriation and crew changes can be organized. If the confirmed case of COVID-19 is found in the board, the nearest port where testing for SARS-CoV-2 may occur, and the local public health authorities should be further managed, including special provisions. It does not matter, and if necessary, contact tracking is performed. The company should establish procedures to cope with potential COVID-19 outbreaks and establish programs for training and practice to prepare for such attacks. Crew members must receive the training necessary to perform the response mission. In particular, if there is a possibility of occurrence or confirmed case, all persons in charge of entering the quarantined area should be educated in terms of complying with all precautions. Training in preparation for this should be regularly organized on ships.

By the public health regulations of the destination country, passengers may request to create a hard copy of the passenger locator before boarding the cruise ship. Passenger locator data should be made available as soon as possible upon request so that public health authorities can initiate contact with exposed passengers. The rapid availability of accurate passenger locator data is critical to the success and effectiveness of contact tracking operations. The health authorities can identify and notify the contact information of infection cases to provide active follow-up management and related advice through this. The easiest way to obtain the passenger data needed for effective tracking will be direct cooperation between cruise companies, port authorities, and public health authorities.

High-level passenger location information obtained through onboard positioning technology can detect close contacts quickly. Firstly, the location information of the confirmed patient and the location information of the passenger are entered. Secondly, location information of the same type as the verified patient can be classified in DBSCAN through location information calculation. It is a technology that accurately identifies contacts within a short period and isolates them according to quarantine regulations based on the location information of confirmed patients and the OD data of passengers. Electronic fences can be installed when contacts are isolated. If a close contact leaves the quarantine area without permission, they are warned through a mobile phone voice trigger device. In short, our technology plan is effective in reducing the risk of virus transmission and can help customer-dependent industries (Figure 2) ^[1].

Contact tracking should be initiated by the health authorities who diagnosed the case and contacted the cruise ship company to quickly identify and contact passengers and crew exposed to the incident. Measures to support and promote such tracking may be as simple as asking passengers to provide contact details for follow-up if necessary. Collection of contact information should be performed electronically and ideally to facilitate and accelerate contacting people at risk and merge this information with a contact tracking database. Note that identifying a single confirmed case transmitted on a cruise would consider all passengers and crew members on board at the time to be high-risk contacts. Therefore, as described above, all passengers must contact and inform management, including quarantine, for 14 days after the last exposure. They should also be advised to seek further advice from the public health authorities to stay on follow-up measures. Movement route information on the number of persons on board can be obtained through onboard positioning technology. Once a person onboard is confirmed, close contacts can be quickly found, reducing the risk of spreading the virus and allowing workers to follow.

Tracking contacts is an essential measure to limit the spread of COVID-19. In general, it is performed only when the diagnostic results are accurate. Still, in cruise ship situations, it is recommended to start contact tracking already while waiting for the diagnostic results. Diagnostic data transmission and rapid testing on cruise ships are available, but they are not currently verified, and confirmation tests are only possible when anchored at the dock. Contact tracking should always be performed in cooperation with public health authorities. If a potential case is confirmed while the ship has not yet arrived at the port, the crew must begin tracking contact on board while checking input into the contact tracking process with public health authorities at the next port. All passengers should be evaluated for exposure and classified as high-risk or low-risk exposure. Passengers who meet the definition of a contact case must request information on the following. It will include contact with the place he visited, that is, a period of two days before symptoms appear. It is possible to quickly implement a contact or group tracking function based on onboard positioning technology.

The contact information of the likely cause should be managed as if the case had been confirmed until the final test results were obtained. If a possible issue is negative, no further action is required. The contract should be described below if the laboratory results are positive. High-risk exposure contacts should be quarantined for 14 days after their last exposure to the case. Hygiene measures, respiratory etiquette should be strictly observed, symptoms should be monitored, ideally provided with a fever reducer, and what to do if symptoms appear. The quarantine facility is correct to be provided on land. Still, if not possible, the contact must stay in a specific quarantine room and provide food and other necessities while ensuring the crew’s safety by providing such services. Crew members carry out cleaning at risk of exposure. A bathroom must be installed in the isolation room.

If two or more people share a room and only one is in high-risk contact, they must move to a single room. When two or more people share a room, if one person has symptoms, it should be managed as a possible cause, and the contact person should be subsequently accommodated in a separate room. After 14 days, the contact person must disembark safely and quarantine on land. Even if symptoms do not occur, the test should also be considered for high-risk exposure. Rapid identification of infection between contacts allows contact tracking to begin as soon as possible.

In-board positioning technology helps track the number of persons on board. This study plan identifies the areas where COVID-19 patients and close contacts stayed for the past 14 days. OD data of the occupant may be extracted using stop point recognition. Since OD data can appear anywhere on the ship, individual OD data is not meaningful. By classifying OD data, we can know which OD data is essential. Therefore, this function will be implemented using the DBSCAN algorithm. Based on this, the scope of the area where the number of persons on board with risk factors stayed is identified.

In this way, quarantine personnel can clarify the goal of disinfection rather than directly disinfecting the entire ship, thereby increasing the efficiency of quarantine work and making the most of existing resources. To realize this, the convex hull algorithm calculates the classified OD data, which could calculate the maximum boundaries of the points, thereby extracting the area where the occupant could stay (Figure 3) ^[1].

The work of ^[2] presents their work on the indoor positioning of users, using a network of BLE beacons deployed in a large wholesale shopping store. The work of ^[3] proposes a Bluetooth location-based indoor positioning system for warehouse asset tracking to achieve a low-cost asset management solution. The work of ^[4] proposes an indoor positioning system to enhance the user experience in museums. The system relies on the proximity and localization capabilities of Bluetooth Low Energy beacons to automatically provide the user with cultural content related to the observed artwork. Evacuating people on board a ship is a typical use case for location services. For example, the traditional evacuation method uses lights, sounds, and signs in a fire onboard a ship. However, this can only be performed if the crew correctly identifies the signs and distinguishes the sounds. It is easy for the crew to lose their calm judgment in dangerous situations. Likely, they will not be able to identify the signs correctly. This is where location services are needed to guide the crew safely out of the situation in real-time.

Moreover, it is not only the crew who need to know where they are. The rescuers also need to know the position of the crew and their position. Location services are, therefore, essential in this case. Once the crew’s location has been obtained, the shortest possible escape route can be planned quickly, reducing the likelihood of danger. In addition, the rescuers can pinpoint the location of a person in danger, thus reducing the rescue time. In this case, no information is required from the crew to rescue them. This is ideal for situations where a person is unconscious. Therefore, there is a vast potential for developing location services for ships.

Moreover, it is not only the crew who need to know where they are. The rescuers also need to see the position of the crew and their position. Location services are, therefore, essential in this case. Once the crew’s location has been obtained, the shortest possible escape route can be planned quickly, reducing the likelihood of danger. In addition, the rescuers can pinpoint the location of a person in trouble, thus decreasing the rescue time. In this case, no information is required from the crew to rescue them. This is ideal for situations where a person is unconscious. Therefore, there is a vast potential for developing location services for ships.