etween 2012 and 2014, Seoul-based photographer Hyung S. Kim frequently visited Jeju Island, which lies off the southern coast of South Korea, to document a small group of women who still carry on an intrepid but dying centuries-old practice. Named the —which literally translates to “ocean women”—these iconic divers harvest shellfish and other sea life from deep underwater without oxygen tanks, requiring that they hold their breath for up to 3 minutes.

Today, many have passed age 60: The youngest diver Kim photographed was 38 at the time, while the oldest was more than 90. They might be the last generation of haenyeo. Captured just after they exited the water, the in Kim’s life-size portraits are situated against a stark, white backdrop, which emphasizes their dirt-speckled shoes and wet, shining gear.

The equipment they carry includes a —the orange sphere some of them have slung over their shoulders, which floats at the surface during each dive—and lead weights attached to their waists to hasten the descent. Kim says he was impressed by their strength and power, even in old age, and wanted to preserve their story on film before it is lost. “They might be the last generation of , and I wanted to document the beauty of these women,” Kim told .

In 2016, the were added to the as the number of divers has dwindled from around 20,000 in the 1960s to just 2,500 in recent years. Although the work was male-dominated originally, it began to reflect the semi-matriarchal.