South Korea's coastguard said Tuesday it had arrested a Chinese national who tried to enter the country after travelling by jet ski from China -- a journey of more than 300 kilometres (186 miles).

Wearing a life vest and helmet, the man crossed the Yellow Sea on a 1800-cc jet ski from Shandong province, using binoculars and a compass to navigate and towing five barrels of fuel.

"He refilled the petrol on the ride and dumped the empty barrels into the sea," the coastguard said in a press release.

When his jet ski got stuck in tidal flats near the western port city of Incheon's cruise terminal, he called for rescue.

The coastguard said the man, who they did not identify, was arrested after he "attempted to smuggle himself into" Incheon.

Authorities said they found no sign that the man was a spy.

The jet-ski escapee is Chinese rights activist Kwon Pyong, according to South Korea-based campaigner Lee Dae-seon of NGO Dialogue China.

Kwon, 35, had posted pictures on social media mocking Chinese President Xi Jinping, and spent time in jail in China for subversion, Lee told AFP Tuesday.

"While his means of entry into South Korea in violation of the law was wrong, surveillance of the Chinese authorities and political persecution of Kwon since 2016 are behind his life-risking crossing into South Korea," Lee said.

"He is now weighing whether to apply for refugee status in South Korea or choose a third country," he said.

South Korea only grants a handful of refugees asylum each year.

The Chinese embassy in Seoul declined to comment when contacted by AFP.

AFP