According to a recent report by Yahoo News in Japan, the Maritime Self Defense Force has received two unmanned underwater vehicles for ocean observation for performance testing. These unmanned underwater vehicles used to observe parameters such as water temperature, salinity, and flow are also known as "underwater gliders". In the future, the Maritime Self Defense Force is expected to use this autonomous underwater vehicle to carry out underwater operations, including intelligence gathering. According to publicly available documents from Hai Zi, these two unmanned underwater vehicle test aircraft are the SeaExplorer X2 developed by French underwater technology supplier ALSEAMAR-ALCEN and the Slocum G3 developed by American company Teledien Webb. It is reported that the SeaExplorer X2 is a multi-purpose unmanned underwater vehicle that can navigate autonomously without the need for engines or propellers to provide power. The front end of the submersible can be equipped with any sensor suitable for the target task, such as an acoustic recorder. When it rises to the surface, it will communicate with satellites to correct its position and transmit the acquired data back. The main functions include remote control, data reception, and position correction through iridium communication. Rechargeable lithium batteries will provide the possibility for long-term observation, allowing for autonomous continuous mission execution for up to 160 days within a 3200 kilometer range. Slocum G3 is an autonomous observation navigation device that can repeatedly float up and dive underwater to conduct long-distance and long-term measurements, thanks to the buoyancy control mechanism of using oil bags and moving the center of gravity of the battery back and forth. Last June, Haizi publicly recruited private enterprises to conduct performance tests on these two types of unmanned underwater vehicles. However, the Public Relations Department of the Maritime Staff Supervision Department recently revealed in an interview with reporters that considering the delivered unmanned underwater vehicles are finished products, the performance testing conducted by private enterprises has been changed to independent research within the Maritime Self Defense Force. It is reported that Haizi plans to conduct independent research on key steps in use before the end of the 2025 fiscal year. An insider from Haizi stated in an anonymous interview, "Haizi's goal is to test these two unmanned underwater vehicles in about two years, ultimately choose one, and form a fleet of 10-12 unmanned underwater vehicles between 2030-2032. They can not only conduct ocean surveys, but also be used for underwater combat." Haizi is currently considering introducing two types of unmanned underwater vehicles for ocean observation, one for observing water temperature structures and other data, and the other for observing seabed terrain and investigating acoustic characteristics. Japan is strengthening its underwater combat capabilities, and the possibility of using unmanned underwater vehicles for mine warfare and anti submarine warfare around the southwestern islands is increasing in the future. (New Society)