"In Jeju Island, there is a community of women, some aged in their 80s, which goes diving 10m under the sea to gather shellfish, such as abalone or sea urchins for a living without the help of oxygen masks. With knowledge of the sea and marine life, the Jeju haenyeo (female divers) harvest for up to seven hours a day, 90 days of the year holding their breath for just one minute for every dive and making a unique verbal sound when resurfacing. Divers are categorised into three groups according to level of experience: hagun, junggun and sanggun with the sanggun offering guidance to the others. Before a dive, prayers are said to the Jamsugut, goddess of the sea, to ask for safety and an abundant catch. Knowledge is passed down to younger generations in families, schools, local fishery cooperatives which have the area’s fishing rights, haenyeo associations, The Haenyeo School and Haenyeo Museum. Designated by the provincial government as representating the island’s character and people’s spirit, the culture of Jeju haenyeo has also contributed to the advancement of women’s status in the community and promoted environmental sustainability with its eco-friendly methods and community invovlement in management of fishing practices."
Source: UNESCO Intangible Cultural Heritage
In Jeju, there is traditional diving to collect the harvest of seas with use of breathing devices. This is from a postcard set that I bought in South Korea.