Lu Chuan, a poor fisherman, is dumped by his fiancée and bullied by local thugs. By chance, he swallows a spirit pearl and gains supernatural powers that allow him to control water and command fish. Relying on his own abilities, he turns his life around and establishes the Nanghai Fleet. He encounters a princess traveling incognito after falling into danger, and together they eradicate pirates at sea. Later, Lu Chuan presents rare treasures to the emperor, is appointed Admiral of Long-Distance Voyages, and marries the princess. Having achieved fame and success, he gives back to his hometown, transforms his fishing village into a prosperous commercial port, and ultimately sets sail to explore the open ocean.