It is the second-biggest vessel in the Chinese navy and so big that sailors on the ship have been issued smart location devices in case they get lost. The People’s Liberation Army has issued staff working on the Hainan, a Type 075 amphibious assault ship, with cards that relay a worker’s position to a central communications hub, state broadcaster CCTV reported on Thursday. The card appeared to be roughly the size of a common access card but thicker and embedded with an “SOS” button on the back. “Our sailors can press the SOS button when they need help, allowing them to connect with the duty communication centre immediately and receive timely help,” Qiu Jijia, the Hainan’s chief communication officer, told CCTV. “This staff card was tailor-made for the Type 075 amphibious assault dock, as it can help the operation commanding centre immediately know the location and activity of the thousands of sailors working on such a huge hull with a complex of cabins.” At more than 230 metres long, the Hainan is second in size only to the country’s aircraft carriers and entered service in April, 2021. More than 2,000 sailors and marines are reportedly working on the new-generation amphibious platform and the staff card includes their personal data. Song Zhongping, a former PLA instructor, said the Chinese-designed staff card was a digital personal tag, similar to the “dog tags” issued to American soldiers deployed to a battlefield. “In the event of a war, the cards allow soldiers to be tracked for timely rescue when needed.”