They’re known as “haenyeo” (“sea women”) of Jeju Island, South Korea, and for centuries, they’ve made their living as divers. Farmland is scarce on the island, and haenyeo harvest food from the sea.

These professional women divers venture 30 feet below the ocean’s surface without oxygen tanks to catch shellfish, conches, abalones, sea urchins and other sea creatures that can be sold for food. They not only share a way of life, but they also share everything they catch.

The sea women of Jeju dive up to seven hours a day, 18 days a month, depending on weather and tide conditions. Most are over the age of 50, and some are well into their 80s.

While historical records from the 14th century mention haenyeo, it wasn’t until the 1600s that women started taking over the profession. No one knows exactly why, but some believe it was because the Korean king did not impose taxes on women’s earnings.  

The journey to becoming a haenyeo is far from easy. An aspiring diver has to earn the vote of every woman in her village and undergo years of training. There are three levels of divers: The beginning level, or hagun, includes older women. The middle level, the junggun, is made up of women who can dive 20 feet down and hold their breath between 40 seconds and one minute, and the top level, or sanggun, are experts who can dive more than 30 feet in the most difficult conditions.

In order to work extended periods of time with only short breaks, haenyeo surface to inhale oxygen and exhale the carbon dioxide created from being submerged for one to two minutes. The whistling sound they make is called sumbisori.

Often the main breadwinners of their families, the female divers of Jeju also promote environmental sustainability on the island, prohibiting harvests at certain times, as well as the harvesting of young fish and shellfish.

Their long history and culture led to the haenyeos’ inscription on the UNESCO List of Intangible Cultural Heritage. The inscription “contributes to improving the status of women in the community and to ecology.”

Numbering around 23,000 in the 1960s, only an estimated 67 female divers under the age of 50 remain, according the island’s Haenyeo Museum. And with their numbers dwindling, this legendary way of life could soon be lost.