For fishermen and sailors in the seaside town of Shangpan in Linhai, Zhejiang province, where recently 12 stranded whales were found, it is not unusual to spot whales or dolphins in the sea – they would always call them haizi, or "son of the ocean".

"And if the local fishermen spot such intelligent sea creatures in need, they will help them without hesitation and rescue them from danger," said Wu Xinjun, deputy Party secretary of Shangpan.

In the recent rescue of melon-headed whales, they tried their best to help.

A 37-second video of a young man sleeping in the water holding a whale soon went viral online, with netizens hailing his relentless efforts and caring heart in trying to keep the whale alive.

"The melon-headed whale knew I was trying to save it and would be more cooperative and wouldn't move," said Lu Wenhui, a 21-year-old diver from Hangzhou Changqiao Polar Ocean Park, who held up the whale's head at a fish farm in Linhai so it could breathe easily.

Lu had been soaked in the water for 10 hours by 4 am Wednesday after coming to Linhai for the rescue work on Tuesday, when the stranded whales were first spotted.

"Whales are mammals and need to breathe in air – that's why I had to hold its head, to ensure it could breathe smoothly the whole time," Lu said.

The stranded whales, after the bumping and jostling of being transported, were worn out when they arrived at the fish farm and might have drowned if they were left unattended.

On Tuesday, 12 stranded melon-headed whales had been found in shallow coastal waters in Linhai, Zhejiang province.

"Three whales were already dead when we found them," said He Xianqing, deputy head of the Taizhou Ocean and Fishery Law Enforcement Team, adding that two died when being released back into the sea.

By 4 pm Thursday, six melon-headed whales had been returned to the sea.