Yung Chang’s grandfather was born along the Yangtze River, and a few years ago the filmmaker and his family accompanied their aging relative on a vacation to his homeland. It was Chang’s first visit to China, and the group sailed upriver on a “farewell cruise.” The tourist cruises began with construction of the controversial Three Gorges Dam, which is flooding hundreds of riparian villages and displacing millions of Chinese. They’re billed as the last chance to see the area’s spectacular landscape. In Up the Yangtze, Chang, who is Canadian, revisits the cruise by following its employees and a group of Western passengers, but he doesn’t remain aboard. Unfortunately, the first-time filmmaker displays more ambition than skill: Far too many disparate themes are never woven together to explain the underlying purpose of the film’s journey.

Shifting from personal narrative to travelogue, and then to social and political commentary, the documentary begins with Chang telling stories about his grandfather, in voice-over narration. A brief description of the genesis of the dam follows: There’s archival footage of Mao swimming in the iconic river as Chang explains that the Three Gorges project was part of the leader’s vision for modernizing China. The filmmaker then becomes preoccupied with catching the passengers and the Chinese cruise operators and their staff in moments that illustrate their racism or class-consciousness, to what purpose is never apparent. Later, the documentary moves ashore to depict the life of one of the cruise ship’s kitchen staff, Yu Shui. Another employee, “Jerry,” who works as a bartender, provides the filmmaker with an opportunity to comment on China’s emerging middle class.

The “farewell cruises” are undoubtedly opportunistic, but bemoaning the presence of rich tourists who are not socially conscious, if that’s Chang’s point, is naive and, dramatically, it doesn’t provide enough depth to sustain a feature film. The dam promises to transition China from its dependence on coal, but Chang doesn’t spend much time explaining the controversy surrounding it. The human toll is explored, briefly, in the most effective sequences of the documentary, when Chang films Yu Shui and her peasant family. Dubbed “Cindy” by her employers, the young woman is compelled to work on the cruise boat to relieve some of her family’s financial burdens. The rising river put her father out of work, and soon it will also subsume their makeshift hut.

In contrast to Jia Zhang-Ke’s narrative film Still Life, an eloquent allegory inspired by China’s dam and new symbol of progress, Up the Yangtze is the shallow rumination of an outsider. Had Chang remained onboard and assumed the identity of bemused observer, the perfect vehicle for someone on the outside looking in, or had he filmed the entire experience of the cruise from Yu Shui’s point of view, the documentary might have resonated with audiences. As it is, there is no reason to climb aboard.