SHANGHAI -- China unveiled two domestic state-of-the-art marine geological survey vessels in Shanghai Tuesday.

One ship, Haiyang Dizhi-8 (Ocean Geology No.8) uses world-leading techniques to create high-resolution three-dimensional images of the seabed's geological structure.

Haiyang Dizhi-8 is 88 meters in length, can cruise for up to 16,000 nautical miles and has a maximum speed over 15 knots per hour.

The other ship, Haiyang Dizhi-9, comes with the world's best deep-water drilling system, able to dig 160 meters into the seabed at a water depth of 2,500 meters.

"The launch, one year ahead of schedule, will boost the fleet of long-serving ships," said Zhong Ziran, head of China Geological Survey.

The new ships are also a great boost to China's marine exploration for oil and gas.

Both ships are seaworthy in all kinds of waters.

China now has six marine geological research vessels in service, launching Haiyang-6 in October 2008.

It plans to unveil Haiyang Dizhi-10 at the beginning of May and put the three new vessels into service by the end of October.