Lin Chuan, who vanished thirty years ago, returns from an ancient bronze coffin on the seabed. He finds his son and daughter-in-law have passed away, leaving only his grandson Lin Xiajia struggling to survive with a run-down fishing boat. Hiding his real identity, he draws close to his grandson and secretly protects him with immortal arts. He helps Lin Xiajia rise up from the oppression of waterfront bullies. Guided by his grandfather, Lin Xiajia establishes Linhai Fishery and inherits the true essence of the *Ocean Command Mantra*. In the end, he uncovers the truth behind his father’s murder, brings the culprit Du Wanjiang to justice, avenges his family and inherits the Lin Clan’s legacy.