Footage shows the complete process of the first successful rescue of a stranded sperm whale in China.

Filmed in the Xiangshan sea area of Ningbo city on April 19, local fishing authorities, fishermen and volunteers were working to rescue the 20-metre-long sperm whale stranded about 740 metres away from the coastline.

Their first attempt failed because the whale was too big so they waited for the high tide to come in.

The tide began to rise in the evening and at 10:42 pm on April 19, rescue ships slowly dragged the stranded whale to where the water depth was about 10 metres.

The sperm whale regained its poise, breathing at a higher rate and jetting water at a higher rate.

Around 11:20 pm, the whale was still floating and there might have been gas accumulation in its body.

The whale was still being towed at around 3 am on April 20. The rescue team planned to release the sea creature 15 nautical miles off the coast after crossing the area crowded with ships at around 5 am.

At 5:30 am the rope was untied and the sperm whale was able to swim by itself.

After a 21-hour operation, the sperm whale finally got out of the trap and returned to the sea. This is the first time China has successfully rescued a sperm whale.

The video was provided by local media with permission.

The video showed complete process of the first successful rescue of stranded sperm whale in China.