Tansuo-2, the mother ship for China's manned submersible that is capable of diving to depths of 10,000 meters, has returned to Sanya in south China's Hainan Province after an 18-month renovation project.

The ship, mainly painted white and green, left from Fuzhou Port in the eastern province of Fujian Thursday before arriving in Sanya Sunday afternoon.

Owned by the Chinese Academy of Sciences, Tansuo-2 adopts an advanced electric propulsion system and positioning system, which can provide sufficient power and automatic cruise capability for deep-sea explorations.

It can carry 60 researchers and serve as the mother ship for China's new manned submersible Fendouzhe (Striver) and manned submersible Shenhai Yongshi (Deep Sea Warrior), capable of reaching depths of 10,000 meters and 4,500 meters, respectively.

The ship is 87.2 meters long and 18.8 meters wide, with a full-load displacement of 6,800 tonnes. It has a maximum speed of 14.2 knots and a cruising range of 15,000 nautical miles, longer than that of the previous-generation Tansuo-1.

The renovation project started in December 2018 at Fujian Mawei Shipbuilding Co., Ltd. Engineers have also upgraded the ship with more labs and increased cabin comfort for researchers.