A still shot from Crosscurrent starring actor Qin Hao. [Photo/Agencies]

Director Yang Chao says his film "Chang Jiang Tu" (Crosscurrent), shown in competition on Monday at the Berlin International Film Festival, is like a love poem for the most important river in China -- and also one of its most damaged.

The film blends elements of the real and the surreal as it follows a quest by the young river captain Gao Chun, played by Qin Hao, as he steers his decrepit hulk of a freighter up the 6,300-km (3,915 m) river to deliver a mysterious cargo.

He is also in pursuit of a beautiful young woman, An Lu (Xin Zhi Lei), who may or may not be a phantasm, and who appears at various places along the river, sometimes to make love to him, at other times to vanish from sight.

During the voyage, Gao Chun reads from a book of poetry that is hidden away in a special compartment on the boat, while the screen flashes verses from famous poets of Chinese history.

"There's a big classical tradition of Chinese poetry and successive Chinese poets from the Tang Dynasty through the other dynasties to the present day have used a variety of approaches to describe, to talk about the Yangtze River," Yang told Reuters.