Li Dahai, a fisherman, accidentally awakens deep-sea X-ray vision. To marry wealthy heiress Su Qing, he strikes a one-year bet with her grandfather. He forms the Haifa Fishing fleet, braves waterspouts, rescues belugas and battles aquaculture tycoons. Finally, he catches the legendary iron-armored giant crab in frigid North Dark Shoal. He wins recognition through his strength and gains his beloved.