Because the volcanic rocks have many holes and the volcanic soil is powdery, most of Jeju’s land is not good for growing crops. This made life on Jeju difficult—many men left for the mainland to make a living, but they never returned or were lost at sea. The Jeju women on the island had to find a way to survive. Inland, the women would mostly grow crops on the small amount of available dry land. In the coastal villages, women known as haenyeo would dive to collect sea plants, octopus, and abalone. They then traded their catch for white rice and cotton, which were not produced on the island.

The history of haenyeo in Jeju dates back to the 5th century during the Three Kingdoms period (18 BCE–660 CE) of Korea. Early records from the Goryeo dynasty (918–1392) also mention female divers of Tamna, one of the earlier names for Jeju Island.

Typically, haenyeo dive for 15 to 20 days every other week, depending on the tides. They stay underwater for 30 to 60 seconds and can hold their breath for up to two minutes. Experienced divers can dive 20 meters (65 feet) deep. Because diving is a risky activity, haenyeo need intensive training. They are trained over many years by other skillful haenyeo in the community. The divers learn about the underwater landscapes and seasonal sea changes, including currents and winds. They also learn how to hold their breath and protect each other in the water.

The haenyeo's diving suits and gear have changed over time. At first, they wore cotton clothes, which were not very warm. During the winter, they could only be in the water for 30 minutes. The first haenoyeo also did not have swim goggles or flippers. They began using these when they became available in the 19th century. Today, haenyeo use modern diving suits that keep their bodies warm in the cold water.

The skilled divers avoid using oxygen tanks. They prefer to harvest only what they can collect within the maximum two-minute breath hold. They do this to prevent overharvesting and to protect the ocean ecosystem. The most essential haenyeo gear is the taewak. It floats in the water and was originally made from a hollowed-out, sealed gourd. The taewak serves as a resting spot, a storage basket, and a location marker. Today, taewaks are often made of styrofoam.

Throughout history, the haenyeo have worked together as a community to protect the ocean and each other. During the Japanese occupation of Korea (1910–1945), they came together to protest unfair treatment. Many people on their island suffered during this time, and the haenyeo were forced to collect the sea algae that would be used to make gunpowder. Thousands of female divers joined protests against the harsh Japanese colonial rule. Their actions were an important part of Korea’s independence movement.

As they dive into the water, they take only what they need from the sea. Their actions show how humans and nature can live in harmony. Now, in the 21st century, haenyeo face new problems, such as sea pollution. Their fight to protect their traditions and community continues.