A Chinese father who calls himself 'Eagle Dad' has made his four-year-old son sail solo.

He Liesheng shot to fame earlier this year when footage of him making his son Duoduo run around in deep snow in his pants went viral.

He says it is concern for his son, not cruelty, that drives him to such extremes.

After six months of training, Duoduo has now taken part in his first solo sailing race, with his father saying: "He is wearing a life-jacket, and he can swim.

"So I think, in fact, although there is still danger, it is greatly reduced.

"Only by placing him in a situation with strong winds and waves can he show his potential."

The results were less than ideal with Duoduo slow to take off, sailing the wrong way and eventually getting stuck against a large yacht.