A jet ski rider who has been detained since he washed up on South Korea’s coast is believed to be a Chinese dissident who feared for his safety and fled by crossing hundreds of miles of sea, trailing barrels of fuel behind him.

The coast guard in the western South Korean port city of Incheon said in a statement Sunday that a Chinese man in his 30s tried to illegally enter the country Aug. 16 by riding a jet ski from the Shandong area of China, an eastern province around 200 miles away across the Yellow Sea.