BEIJING - An unmanned submersible has passed its final field test, marking another step in China's drive to explore deep sea resources.

Named "Haima," or sea horse, the vehicle can dive a depth of 4,500 meters via remote control and has the highest proportion of China-made parts compared with the country's other submersibles, according to a statement released on Tuesday by the Ministry of Science and Technology.

Chinese scientists spent six years developing core technologies and making the machine, which went through multiple improvements following problems and malfunctions during tests in laboratory tanks and the ocean.

During tests, the vehicle achieved a maximum depth of 4,502 meters, and reached the central basin in the South China Sea for tasks such as deploying cables, collecting sedimentary rock samples and photographing.

The ministry said the vehicle enables the country to strengthen its hi-tech exploration of deep sea resources, and the ministry will cooperate with the Ministry of Land and Resources in devising work plans for Haima.

Meanwhile, Qianlong-1, another unmanned submersible still in the trial stage, is designed to travel to a depth of 6,000 meters and will be tasked with exploring the seabed and collecting hydrological data.

In 2012, Jiaolong, the country's most advanced manned submersible, achieved a record dive depth of more than 7,000 meters in the Pacific's Mariana Trench.