Fisherman Chen Hai has his livelihood destroyed when Lai Guangtou, a local dockside bully, deliberately drives down the prices he pays for seafood. With his seriously ill father in urgent need of medical expenses, Chen Hai finds himself at his lowest point. His only hope is an ancestral handbook, The Tides: A Guide to Coastal Foraging. By mastering the tides and harvesting seafood legally, he discovers rare marine delicacies and establishes a direct supply channel to high-end hotels. Chen Hai buys a fishing boat and establishes a fishing cooperative, offering fishermen fair market prices and breaking Lai Guangtou's long-standing monopoly. He repeatedly foils Lai's schemes, including boat sabotage, false accusations, and tampering with marine weather warnings, ultimately helping law enforcement dismantle the criminal seafood trading network. He then leads the entire village in developing lawful fisheries, cracks down on dishonest influencers exploiting coastal foraging for profit, and establishes Deep Blue Fisheries. Together, he helps fishermen throughout the town build secure and prosperous lives through sustainable coastal resources.