At two ends of the world, communities separated by thousands of kilometers share a common way of living with the sea. From the haenyeo —the legendary women divers of Jeju Island— to professions such as rederas, bateleras or rowers on the Basque coast, the documentary builds a sociocultural bridge between territories that may seem distant, yet are deeply connected through shared values, rhythms of life, and their relationship with the natural environment. Through everyday gestures, personal stories and collective memory, parallels emerge that speak of physical effort, inherited knowledge, and identities shaped in direct contact with the sea. The documentary proposes a dialogue between past and present, between tradition and transformation. In a context of rapid change, where many of these professions face an uncertain generational continuity, the protagonists sustain practices that are not only forms of work, but ways of life closely tied to community and ecological balance. At this cultural crossroads, Daughters of the Sea reveals a living heritage that endures. A legacy that is passed on, adapted, and defended against global homogenization. Beyond borders, the ocean becomes a shared language — a space of memory, identity, and future.