BEIJING, Feb. 2 -- China's manned deep-sea submersible Jiaolong and research vessel Dayang Yihao (Ocean No.1) are set to complete major upgrades in preparation for deep-sea exploration missions this year, according to the country's oceanic affairs administration.

Jiaolong, named after a mythical sea dragon, is capable of diving to depths exceeding 7,000 meters. The China-made underwater ship has explored waters in the Pacific Ocean, Indian Ocean and Atlantic Ocean.

Its upgrades are currently in progress, and technicians have already completed major enhancements to its critical components, including the lithium battery system.

The sea dragon-inspired submersible is scheduled to undergo tank tests in February and sea trials in the South China Sea in March.

Major upgrades on Ocean No.1 include the installation of remotely-operated underwater vehicles, which will enhance its capabilities and provide reliable support for future deep-sea resources survey and development, said the administration.

Ocean No.1 is China's first modern comprehensive ocean-going scientific research vessel. With over four decades of service, it has conducted 27 oceanographic scientific expeditions.