The three crew of China's deep-sea submersible Jiaolong stepped aboard the mother ship Friday after their historic dive to the deepest place on the planet to be welcomed with a bucket of water over each of their heads.

The unorthadox welcome was the crew's way of celebrating their safe return after setting a national record for a manned deep-sea dive.

Ye Cong, Cui Weicheng and Yang Bo steered the Jiaolong vessel 6,671 meters into the Mariana Trench, far surpassing the 5,188-meter record it set last July.

"It is really an unexpectedly good result," said Liu Feng, the on-scene commander.

The dive, which began at 9 a.m. local time (2300 GMT Thursday), is the first of a series of six scheduled in an attempt to achieve the country's first 7,000-meter manned dive.

The dive went smoothly, taking the submersible about three hours to reach a depth of 6,000 meters. At 6,055 meters, the three divers wished China's Shenzhou-9 spacecraft launch a success.

The Shenzhou-9 manned spacecraft Thursday completed its final full-system drill before its planned launch on Saturday.

The Jiaolong threw ballast iron and began to rise at 12:44 p.m. local time (0244 GMT) after it had reached 6,671 meters.

A problem did arise during its rise, when the submersible's No. 1 communication system failed, but the No. 2 set worked soundly to guarantee the connection between the vessel and the mother ship.

The Jiaolong, depending on local weather and sea conditions, will try another five dives in the coming days, aiming to move deeper and deeper toward the 7,000-meter target.

The six dives, each of which may last eight to 12 hours, will test various functions and performances of the manned submersible at great depths.

Experts say, for safety reasons, sea dives can only be conducted in daylight in no more than class-four winds and no more than class-three waves.

The Xiangyanghong 09 mother ship reached the designated dive zone in Mariana Trench on Monday morning.

"The Jiaolong will be turned over to the China Ocean Mineral Resources R&D Association (COMRA) for practical applications after the test dives," said Liu Cigui, director of the State Oceanic Administration. (Xinhua)