More than 2-thousand cultural relics have been recovered from the Nan'ao One, an ancient Chinese merchant ship that sunk off Guangdong Province more than 400 years ago. Paul Crowe takes a closer look at the salvage operation which resumed last month.

The shipwreck lay at the bottom of the South China Sea for more than 400 years before it was discovered by chance. A group of fishermen found it four years ago off Nan'ao island, a cluster of small islands off Guangdong Province.

The ship is 35 meters long and 8 meters wide, and is the first late Ming dynasty ship ever discovered.

Initial excavation work began in 2009, but suffered setbacks due to poor weather and sea conditions.

This year marks the fourth round of salvage operations.

Cui Yong, Team Leader of Nan'ao One Underwater Archeology Team said "The underwater relics are well preserved. We've found the cords we left last year are still intact, so we'll continue the work suspended last year."

About 2000 relics have been recovered since April 26th, when the operation began. Most of them are dishware such as plates, tins and bowls with exquisite graphics and paintings.

Out of nearly 3 million sunken ships in oceans around the world, the South China Sea has the most. It's estimated it has more than 2000 ancient ships.

The Underwater Archeology Center of China was set up in 1986, when the country felt the urgency of exploring the undersea world. After 20 years' development, archeologists from the agency have taken part in many underwater treasure explorations.

Cui Yong said "We're on a fast growing track, our workload may be the largest over past 20 years, we've been working in many coastal provinces and abroad. We're moving neck and neck with other countries technically. The integral salvage of Nan'ao No.1 is unprecedented, I think our country is taking the lead in this regard. "

This salvage of Nan'ao No.1, the best preserved sunken ship from the Ming dynasty, is expected to last until July. The relics from the vessel are valuable for the study of ancient porcelain production technologies and the country's ancient "Marine Silk Road", a passageway for ancient China to the outside world.