NANNING -- At least once a month they gather on decks or in the red-roofed house at the center of the water, sitting on stools to hear or study the latest theories and policies of the Communist Party of China (CPC).

For the 6,000 residents of Tianshengqiao township, Longlin county in south China's Guangxi Zhuang autonomous region, the "lecture on water" is the most popular and effective channel to understand Party policies. Speakers are mainly village and township Party chiefs. Local technological advisors are also invited to teach aquaculture.

Liu Jian, Party chief of Tianshengqiao, has been a frequent speaker since he took office in this small remote mountain town in October 2016. He says most of the population belongs to ethnic minorities, including Zhuang, Miao and Gelao.

The villagers used to grow rice. After the construction of a hydropower plant in the 1990s, they farmed fish and began living off the reservoir, which borders Yunnan and Guizhou provinces.

"Most villagers spend all day on water, busy working. They have little time or opportunity to learn about the world outside," says Liu.

Seen from the mountains, the floating fish pens, large and small, checker the green lake like a chessboard.

The red-roofed "lecture room", at the center of the reservoir, is particularly eye-catching. Local people call it the "New Era Institute of Peasants", which is believed to be a nod to the Peasant Movement Training Institute of 90 years ago.

In the 1920s, revolutionary pioneers of the CPC, including Deng Xiaoping, set up peasant movement institutes in remote mountain areas in Guangxi. They publicized revolutionary theory, conducted military training, and organized armed struggles, which laid the foundation for the uprisings and revolutionary bases.

In past decades, local Party officials gathered villagers at the meeting room of a government building in the town center to hear reports. Because of the long distances and worries about their work, few people were willing to go. "The attendance was low and people were not happy," says Liu.

In 2014, the Tianshengqiao Township Committee of the CPC decided to move the meetings "onto the water".

"We used to sit on the podium, waiting for an audience. But now we stand on a boat and get close to villagers, telling them events and policies from Beijing," says Liu.

Villagers travel by boat to the meetings. Lectures usually last 40 to 50 minutes and attract more than 20 boats each time. Audiences can reach a hundred.

Some people wear Party emblems and some come in colorful ethnic costumes. The elderly bring their grandchildren, and women weave while listening. Some people take notes.

Speakers use local dialects and the Zhuang language. Though outsiders do not understand, the locals appreciate it.

Speeches with difficult concepts are "translated" into examples and stories based on simple daily life.

Liu in recent lectures explained the essence conveyed at the 19th National Congress of the CPC, stressing the content about "pursuing a rural vitalization strategy" and "safeguarding the property rights and interests of rural people".

A meeting last month focused on medical insurance. Some villagers thought it was unnecessary, but after half an hour of discussion, they realized the benefits.

Liu convinced them that insurance would save money on treatment: "Without insurance, you will pay more if you go to hospital. Moreover, the local government has offered reimbursement of fish farmers' medical bills. It would not cost much."

On the water, speakers' voices are louder and gestures more frequent. But they no longer fear losing their audience. Laughter often echoes on boats.

It is also a popular class on fish farming. In the early years of the reservoir, people did not understand how to farm fish. Pursuing high production led to fish diseases, severe pollution and huge losses.

Shi Zhongyu, a local aquaculture expert, lectures three or four times a year on the water. "In the past, the fish farmers could hardly make a living, because they lacked knowledge and training," he says.

Every winter, he tells the fish farmers to lower fishing net density and not to feed too much, so as to maintain nutrition levels. He can explain, while demonstrating, how to feed on the water - an impossible task previously.

In 2012, only 15 households were fish farmers, but now the number is 200 - almost half the town's population.

Wei Bin attends every "lecture on water" with his wife. They understand the economic benefits of the classes.

Through lack of knowledge, he lost tens of thousands of yuan in 2012. But his annual income has risen from 1,000 yuan to more than 10,000 yuan over the past four years.

Aquaculture has become a pillar industry in the county. In 2016, two of five poverty-stricken villages were lifted out of poverty.

Longlin County has 31 villages setting up "lecture rooms". Some are known for speakers using folk songs to explain national policies so the less-well-educated can understand.

"We plan to expand the speaking team by inviting ethnic villagers or experienced fish farmers. They will make the lectures on water more attractive," says Liu.