Chinese rescuers say they located the sunken tanker "Sanchi" on Tuesday morning. They are still sending robots to approach the vessel for further assessment. Chinese rescue teams have been sending aircraft to the site of the accident to check on the extent of the oil leakage and search for the 29 missing crew members. Our camera crew follows one of the flights, as Hang Peng reports.

A bird's-eye view reveals the scale of the catastrophe. What used to be a week-long flame in the middle of the ocean is now the center of a major oil spill, covering 133 square kilometers in one of the world's richest fishing grounds.

The spilled condensate is clearly visible from over 1,000 meters above the sea. The silver stripes are what's left after the oil tanker carrying a million barrels of condensate exploded and sunk after a week of burning.

Regular crude oil leaves a thick, black slick. Experts say the condensate the Sanchi had been carrying is more volatile and less of a pollutant. But they also warn the chemicals may enter the food chain. The clean-up may take decades.

ZHOU YONGDONG, DEPUTY DIRECTOR ZHEJIANG MARINE FISHERY RESEARCH INSTITUTE "The oil leakage will impact different types of marine animals differently, and it varies from how fast they are able to travel. For example, an octopus will move slower than a normal fish. Plus, the sea usually has its own self-purification mechanism. But because the composition of the condensate oil is quite complicated, I do not know how long the impact will last."

On Tuesday, China reinforced the operation with a professional cleaning vessel. Now a total of 13 vessels from China, Japan and South Korea are spraying dispersants on the spilled condensate. The boats are also using absorption mats to clean up what's left. Han Peng, CGTN, Zhoushan.