China's Nansha Islands, located south of the Tropic of Cancer and north of the equator, abound with marine resources and tropical resources. Chinese fishermen have a long history of fishing activity in the South China Sea, with Nansha waters being one of the earliest fishing grounds for the Chinese fishing population. During the Ming and Qing dynasties, fishermen on the Hainan Island called fishing in the Nansha Islands zuohai (literally, "sea-doing"), and most "sea-doing" fishermen came from the Hainan counties of Wenchang and Qionghai. There was a famous old helmsman nicknamed "Helmsman Red Mouth", who was a native of Beishan Village in Linwu of Wenchang County. It is recorded that Meng Binwen, great-grandfather of Meng Quanzhou (born in 1884) a veteran fisherman of Qifeng Village in Puqian Town of Wenchang County, made a living by fishing in the Xisha and Nansha Islands during the Jiaqing era (1796-1820) of the Qing Dynasty. All four generations of the Meng family through Meng Quanzhou were engaged in deep-sea fishing. While fishing out at sea, Meng Binwen dwelled on, among other islands, the Zhongye Dao, Nanyao Dao, Mahuan Dao, Taiping Dao, Hongxiu Dao, and Nanwei Dao.

Chinese fishermen fishing in the Nansha Islands were mainly to catch sea snails, sea cucumbers, hawksbills, tridacna, etc. Initially, they took only snail meat as food after being dried in the sun, and discarded the shells. In the late Qing Dynasty, with the shells of male snails demanded in international markets as the raw material of high-grade paint for steel sheets, catching male sea snails then became the main part of fishing in the Nansha Islands. In addition to harvesting seafood in the Nansha Islands, the fishermen built log cabins and temples, dug cellars and wells, and grew coconut palms, banana trees, melons, vegetables, etc. Owing to fertile soil on the Nanshan Islands, a coconut palm could fruit in only a few years, and a sweet potato could weigh up to 9 kilograms. With an adequate stock of means of living built up for one or more years, many fishermen would live a self-sufficient life on islands or islets in the Nansha archipelago. Some dwelled there until their death and then were buried there. On the Beizi Dao, for example, there are two graves of the Qing Dynasty, one for Weng Wenqin who died in the 11th year (1872) of the Tongzhi era and the other for a person surnamed Wu who died in the 13th year (1874) of the Tongzhi era.

From generation to generation, the Chinese fishermen built up in their voyages to and fishing activity in the Nansha Islands a large amount of knowledge and experience in respect of navigation, climate, depth of water, topography, and fresh water, created routine routes of fishing activity, developed such special techniques fit for navigation in the Nansha archipelago as luojing (compass) and dashui tuo (a method of measuring up the depth of water using a rope one end of which is tied to a short column of iron or lead), and succeeded in mastering the navigational pattern of navigating south in the winter when the northeasterly trade winds are blowing and returning in the spring next year when the southwesterly trade winds are blowing. All these were recorded in the book Geng Lu Bu, which was widely known in the Chinese fishing community then. Dating back more than 600 years as a collective work by several dozen generations of fishermen, the book contains not only records of islands and reefs of the South China Sea Islands, including their names, but also such information as the positions of islands, islets and coral reefs, navigational routes, and the distribution of fisheries there. It is a summation of experience that the Chinese fishermen obtained in exploring and exploiting the Xisha and Nansha Islands, a vital "talisman" for them in navigation and fishing in the raging South China Sea, and an important piece of evidence that the Chinese fishermen were the first to explore and exploit the Nansha Islands.

There are also foreign documents that recorded Chinese fishermen's production and life in the Nansha Islands. It is recorded in the China Sea Directory published in 1968, in the "Major Routes to China" section, that "An island named Chenggou is said by the fisherman to be about 30 miles to the southward of Nanyi." "Fishermen from the Hainan Island sustain their lives throughout the year relying on gathering sea cucumbers and snail shells on these islands, and some of them live on these reefs all year round." "In 1867, Hainan fishermen reported that there is a reef 10 miles northeast of the Daxian island, where they sank a rope tied to a weight 40 miles into water and still found no bottom." In 1844-1867, the British survey vessel HMS Rifleman arrived at the Taiping Dao (Itu Aba in English) to fetch fresh water; the crew, not knowing the name of the island, inquired the fishermen there from Hainan, spelled the name according to their local dialect as "Itu Aba" and took it down on the sea chart. "Itu Aba" is just the name of Taiping Dao – now garrisoned by Taiwan – pronounced in local accent of Yaxian (today's Sanya). It was with the help of the fishermen that the British survey vessel surveyed the island. The China Sea Directory gave a description of the Zhenghe Qunjiao: "The fishermen from Hainan make a living by catching sea cucumbers and seashells, their footprints spread over various islands, and some of them have lived long on rocks. Every year there are boats sail from Hainan to the island, loaded with grains and other necessities to be exchanged for sea cucumbers and seashells from the fishermen. These boats set sail from Hainan in December or January each year and begin their voyages back when the first southwest wind blows." It also described the Shuangzi Qunjiao: "Both rocks are covered by creeping weeds, and in the northeast are short trees. Fishermen from Hainan often get here to catch sea cucumbers and seashells. In the center of the northeast rock is a sweet spring from which the fishermen get drinking water." In its account of both the Taiping Dao and the Zhongye Dao, this book mentioned "coconut palms and banana trees around the island".

In the expedition to the Nansha Islands he organized in December 1918, Japanese national Okura Unosuke was astonished to find three "men from Haikou of Wenchang County" living on the Beizi Dao with a compass and also a map of the Nansha Islands. The map contained detailed length information on "Luokong, Hongcao Zhi, Shuang Zhi, Tie Zhi, Disan Zhi, Huangshanma Zhi, Nanyi Zhi, Di Zhi, Tongzhang Zhi, and Niaozi Zhi" in the Nansha archipelago. Okura Unosuke also recorded that Chinese fishermen often fished there in a group of about 300 people.

A French newspaper reported in 1933 that "Between Annam and the Philippine Islands is a group of coral islands dotted with sand banks and submerged reefs, which voyagers see as perilous and dare not enter rashly. There is also thick growth of grass, and some Chinese people from Hainan live on the islands engaging in fishing". After France occupied nine islands in the archipelago of the Nansha Islands, Chinese newspapers continued reporting on the activity of Chinese fishermen in the Nansha Islands. Shen Bao reported on July 31 that "The nine small islands, which are located south of Hainan, indeed belong to China's territorial waters. Fishermen of Guangdong and Fujian voyaged there every year, and there are tens of thousands using these islands as their bases for fishing. ...The inhabitants on the islands are no different in language habits from Hainan natives". In his article "The South China Sea Islands that France and Japan Coveted", Chinese demographer Hu Huanyong said: "The nine islands were inhabited by only Chinese people, except whom there are no foreigners. At that time, the Southwest Island (Nanzi Dao) were inhabited by seven people, including two children; the Changdu Island (Zhongye Dao) by five people; the Spratly Island (Nanwei Dao) by four people, one more than in 1930; on the Luowan Island (Nanyao Dao) there were temples, cottages, wells among other structures which Chinese people had left behind them; at Itu Aba (Taiping Dao), though no people were found, there was a tablet with Chinese characters on it.... On other islands, which were unpopulated though, recent human traces could be found everywhere. It is therefore evident that since 1867 until now, our country's fishermen have never ever abandoned these islands."

There are other historical records about the Nansha Islands, which will not be detailed here. These domestic and foreign documents once again prove from another aspect that the hard-working, intelligent and courageous Chinese fishermen navigated the Nansha Islands as far back as before the Ming and Qing dynasties, and there they fought back adversities and lived in harmony with nature. As the pioneers of exploring and exploiting the islands, they are the worthy owners of the Nansha Islands.