Haiyan, the advanced, automated underwater glider developed by China, set a world record by diving 8,213 meters, almost 1,900 meters deeper than the previous best, engineers said on April 22.

Experts said the dive represents a major milestone in the development of China’s underwater research equipment, which will collect valuable data for scientific, economic and military purposes.

Haiyan, Chinese for storm petrel, a kind of bird, made the dive in the Mariana Trench, a scythe-shaped cleft in the western Pacific Ocean floor that plunges nearly 11 kilometers, Wang Yanhui, the glider’s project director, told China Central Television.

The dive was one of the experiments carried out by crew members aboard the scientific survey ship Xiangyanghong 18 during a 30-day voyage. The ship returned to Qingdao, Shandong province, on April 21.

“We fully tested the performance of Haiyan deepsea underwater gliders in a series of trials,” Wang said.

There were two types of Haiyan gliders tested during the voyage. One could reach a maximum depth of 4,000 meters; the other could reach 10,000 meters, he said.

During the six days of dives into the Mariana Trench, the deepest location on Earth, Haiyan broke the previous record of 6,329 meters set by another Chinese sea glider, Haiyi.

“It is a historic step in China’s deep-sea observation,” said Wu Lixin, director of Qingdao National Laboratory for Marine Science and Technology. “The successful development of the deep-sea underwater glider will guide the advancement of China’s unmanned deep-sea research equipment.”

Tianjin University began developing the Haiyan series in 2002. Since 2006, Haiyan gliders have been deployed to collect key hydrologic data for scientific projects in bodies of water throughout China and nearby seas.

A glider is an autonomous underwater vehicle designed to survey marine conditions such as temperature, salinity and currents in large bodies of water.

Since the 1960s, advanced underwater gliders have been a key gauge of a nation’s marine capabilities, and countries including the United States and Japan have closely guarded the technology.

Military-grade underwater gliders can be equipped with long-range sensors to detect mines, submarines or combat divers. They can also carry weapons for underwater patrols or assault missions, said Senior Colonel Ma Gang, a professor at the People’s Liberation Army’s National Defense University.

Noncombat underwater gliders can collect valuable ocean data that is crucial for naval formations, submarine routes and battle planning, Ma said.