Off the coast of Jeju Island, women dive into the ocean without oxygen tanks. They have been doing this for at least 1,500 years. They dive to depths of up to 20 meters, hold their breath for two to three minutes at a time, and surface carrying sea urchins, abalone, and conch in their nets. The youngest active haenyeo are in their forties. Many are in their seventies and eighties. Some are still diving past ninety.
The haenyeo (해녀) — literally "sea women" — are one of the most remarkable human communities in the world. They are not a legend or a myth. They are real, they are still working, and the physiological and cultural mystery they represent has attracted the attention of researchers from medicine, anthropology, and evolutionary biology.
Because the haenyeo are not simply skilled divers. They are women whose bodies, over generations of selection and training, appear to have changed.
Who the haenyeo are
The haenyeo tradition is centered on Jeju Island — the large volcanic island off the southern tip of the Korean peninsula — though haenyeo communities have historically existed along the southern coast of the mainland and in parts of Japan as well. The Japanese equivalent, called ama (海女), shares a common origin with the Korean haenyeo and represents the same ancient diving tradition.
At their peak in the mid-20th century, there were estimated to be around 30,000 haenyeo on Jeju alone. Today, the number has fallen to approximately 3,500 — almost all of them elderly, as younger generations have not entered the profession in significant numbers. The tradition is on a trajectory toward extinction within a generation or two, which is one reason it was inscribed on UNESCO's Intangible Cultural Heritage list in 2016.
| Feature | Detail |
|---|---|
| Active diving age range | From training in childhood to active diving into the 80s and occasionally 90s |
| Dive depth | Typically 5–10 meters; experienced divers regularly reach 15–20 meters |
| Breath-hold duration | Average 1–2 minutes per dive; experienced divers up to 3 minutes |
| Daily dive cycles | Up to 90 dives per working day during peak season |
| Water temperature | As low as 10°C (50°F) in winter, without modern wetsuits historically |
| Equipment (traditional) | White cotton suit, goggles, net bag; no oxygen, no fins, no buoyancy aids |
The physiology of the haenyeo
Medical researchers began studying haenyeo physiology systematically in the 1960s and 1970s, and what they found surprised them.
Haenyeo demonstrate measurable physiological differences from non-diving women of the same age and background. Their resting metabolic rate is significantly higher than average — an adaptation to cold water immersion that allows their bodies to generate more heat. Their heart rate during dives drops sharply and rapidly — a pronounced diving reflex that conserves oxygen and protects the heart and brain during breath-hold. Their lung capacity is above average, and their tolerance for carbon dioxide buildup — the physical sensation that triggers the urge to breathe — is measurably higher than in non-divers.
A 2021 study published in Cell found genetic evidence suggesting that Jeju Islanders carry specific genetic variants associated with cold tolerance and cardiovascular response to diving — variants that appear at higher frequency in the Jeju population than in mainland Korean populations. The researchers concluded that natural selection may have acted on the Jeju diving population over generations, favoring physiological traits that improve diving performance and survival.
This would make the haenyeo one of the very few human populations for which recent natural selection for a specific occupational adaptation has been documented.
The social world of the haenyeo
The haenyeo tradition created one of the most unusual social structures in Korean history. Because haenyeo were the primary economic providers in their households — their catches were more reliable and more valuable than the agricultural work available to men on rocky Jeju — Jeju developed a matrilineal social culture that was distinctly different from the patriarchal Confucian norms of mainland Korea.
Haenyeo worked in cooperatives called bulteok communities, organized around a shared changing hut (the bulteok) where women gathered before and after dives to warm themselves, share food, and conduct the social business of the community. The bulteok was a women's space — men did not enter. Within it, haenyeo discussed prices, resolved disputes, organized collective action, and transmitted knowledge from older divers to younger ones.
The hierarchy within haenyeo communities was determined entirely by diving skill. The most experienced and capable divers — called sanggun — held the highest status. Age alone was not sufficient; a woman had to earn her rank through demonstrated ability in the water.
The spiritual dimension
The haenyeo relationship with the sea was not purely economic. It was spiritual, and it was honest about danger in a way that modern occupational culture rarely is.
Before diving season, haenyeo performed shamanistic rituals called gut, led by a mudang (shaman), asking the sea goddess Jamsugwisin for safe passage and abundant catches. These rituals acknowledged directly what the haenyeo knew from daily experience: the sea could give, and the sea could take. Women died diving. It was not common, but it happened, and the community's spiritual practices were designed around that reality rather than around its denial.
The sound most associated with haenyeo is the sumbisori (숨비소리) — the distinctive whistle they make when surfacing, exhaling carbon dioxide-rich air and drawing in fresh oxygen in a controlled technique developed over generations. The sumbisori is both a physiological necessity and, for those who hear it from shore, an eerie, beautiful signal that the diver has survived another descent.
The curious connection
The haenyeo story sits at an intersection that rarely appears in human history: a community of women who, through occupational necessity and cultural continuity, may have physically changed what it means to be human in their specific environment.
The genetic evidence from the 2021 Cell study places the haenyeo in a very small group of human populations for whom natural selection for recent, specific adaptations has been documented. Other examples include Tibetan populations with adaptations for high-altitude oxygen efficiency, and Bajau sea nomads of Southeast Asia with enlarged spleens for extended breath-holding.
What these populations share is not remarkable genetics in a broad sense. They are remarkable because they stayed in one place, doing one thing, long enough for natural selection to act. In a world of increasing mobility and occupational diversity, this kind of deep, sustained, multigenerational commitment to a specific way of living is becoming vanishingly rare.
The haenyeo are disappearing. The youngest generation is not diving. The genetic variants, the physiological adaptations, the bulteok communities, the sumbisori — all of it is on the edge of being lost. What the haenyeo represent is not just a cultural tradition or an economic practice. It is a demonstration of what human beings can become when they commit, generation after generation, to a relationship with a specific part of the world.
When the last haenyeo retires, something genuinely irreplaceable will be gone.
FAQ
What are the haenyeo?
The haenyeo (해녀) are a community of female breath-hold divers from Jeju Island, South Korea, who have been harvesting seafood from the ocean without breathing equipment for at least 1,500 years. Their tradition was inscribed on UNESCO's Intangible Cultural Heritage list in 2016.
Why are all haenyeo women?
The historical reasons are not fully documented, but by the Joseon Dynasty period, female diving had become dominant on Jeju, likely because women's physiological cold-water tolerance proved superior and because the economic value of haenyeo income gave women unusual social status on the island. Men fished from boats; women dived.
How long can haenyeo hold their breath?
Experienced haenyeo typically hold their breath for one to two minutes per dive, with some reaching three minutes. They may complete up to 90 dives in a working day, with brief surface recovery periods between each descent.
Are the haenyeo still active today?
Yes, but their numbers have declined dramatically. From a peak of approximately 30,000 in the mid-20th century, the active haenyeo population on Jeju has fallen to around 3,500 — almost all elderly. The tradition faces extinction within a generation as younger women have not entered the profession in significant numbers.
What did the 2021 genetic study find about haenyeo?
A 2021 study published in Cell identified genetic variants in the Jeju Island population associated with cold tolerance and cardiovascular diving response that appear at higher frequency in Jeju than in mainland Korean populations. The researchers suggested natural selection may have acted on the diving population over generations, making haenyeo one of very few human groups with documented recent occupational genetic adaptation.