China's newly-developed SeaWing 1000 underwater glider has set a new national record after working continuously for 91 days without any malfunction in the South China Sea. 

The glider was retrieved by scientists from Shenyang Institute of Automation (SIA) under Chinese Academy of Sciences (CAS) on Thursday. During its 1,884-kilometer voyage, the glider collected the data of altogether 488 cross-sections. Both its sailing distance and data volume set the national records as well. 

"The biggest difference between an underwater glider and a traditional underwater robot is that the former does not have a propeller, but an oil sac like a fish maw. By changing the size of the sac, the glider can change its net buoyancy so that it can move up and down. A pair of 'wings' on it will generate a thrust along the horizontal direction of moving forward, which will finally enable the glider to leave a W-shaped trail while moving underwater," said Yu Jiancheng, a researcher with the SIA. 

The SeaWing 1000 glider was launched in the northeastern part of the South China Sea on July 14 this year, for a networking observation mission together with another 11 underwater gliders and was kept underwater in the sea area for a cruising endurance test after the mission was over. 

During the 91-day voyage, it survived hazardous sea conditions triggered by five typhoons in succession, which fully demonstrated its reliability and stability. 

The new endurance record doubled the previous one and made China the second country in the world that is capable of conducting cross-seasonal autonomous underwater observation.