A boy sits on the pilot seat aboard the Dong Hai Jiu 101 rescue vessel during a ship open day activity marking the 2018 Maritime Day of China in east China's Shanghai, July 11, 2018. The 2018 Maritime Day of China was observed on Wednesday. (Xinhua/Fang Zhe)

A crew member (R) interacts with a young visitor to the Dong Hai Jiu 101 rescue vessel during a ship open day activity marking the 2018 Maritime Day of China in east China's Shanghai, July 11, 2018. The 2018 Maritime Day of China was observed on Wednesday. (Xinhua/Fang Zhe)

Local residents visit the Dong Hai Jiu 101 rescue vessel during a ship open day activity marking the 2018 Maritime Day of China in east China's Shanghai, July 11, 2018. The 2018 Maritime Day of China was observed on Wednesday. (Xinhua/Fang Zhe)

Sailboats are seen on the Huangpu River during activity marking the 2018 Maritime Day of China in east China's Shanghai, July 11, 2018. The 2018 Maritime Day of China was observed on Wednesday. (Xinhua/Fang Zhe)

A crew member (1st L) introduces the bridge of the Dong Hai Jiu 101 rescue vessel to visitors during a ship open day activity marking the 2018 Maritime Day of China in east China's Shanghai, July 11, 2018. The 2018 Maritime Day of China was observed on Wednesday. (Xinhua/Fang Zhe)