A vessel formation with China's Nanhai Fleet on Wednesday sailed across the Bashi Channel toward its destination in the West Pacific Ocean for a combat drill, according to sources with the People's Liberation Army.

The team will join other formations and planes from the Beihai Fleet and Donghai Fleet in the drill, which is expected to improve the combat system, hone strategies for utilizing information technologies, coordinate ships and planes and conduct integrated defense.

The drill, which is in line with international laws and practices, marks the first open sea drill in which maritime and air forces of the three fleets will jointly participate.

"With a more complicated hydrological environment, open sea combat demands stronger intelligence warning and detecting abilities as well as higher requirements for communication and command system equipment," said Lin Hai, head of a command group in the drill.

The Bashi Channel is an international waterway linking the South China Sea and the Pacific Ocean.