When misfortune strikes the fishing family of Lin Haiyan, her father is injured and debt collectors come knocking. Using their fishing boat as collateral, she makes a promise to repay the debt within three days. Armed with a secret tide chart passed down through generations, she fearlessly ventures into dangerous deep waters, repeatedly foiling the intimidation and schemes of the local strongman. With the assistance of scientific researchers, she leads the villagers in establishing a fishing cooperative and pursuing sustainable fishing and brand development. Expanding from coastal waters into the open ocean, she leads her fishing village out of hardship and carves out a path to prosperity for the next generation of fishing families.