Lei Mu, a modern ocean captain, transmigrates into a teenage boy in a fishing village of the 1990s. Trapped in a debt scheme set by local tyrant Qian Hai, he relies on his seafaring skills and business wits. He starts by catching rare seafood in Black Trench, survives a deadly sabotage to his boat, and sets up a fishery cooperative. He opens foreign trade channels, brings the tyrant and his backers to justice, and leads all villagers out to the open ocean.
