A tense high-seas adventure with substance and heart, co-scripted by Bong Joon-ho (“The Host,” “Snowpiercer”), this spectacle of a thriller is exactly why Hollywood is beating a path to South Korea’s door. Kang is captain of a fishing boat crewed by rough men who are used to the harsh realities of life at sea. Regular fishing runs net a meager income, and Kang has a problem with his wife. So he finds it impossible to pass up the lucrative, but highly risky, opportunity to smuggle a group of illegal immigrants from China to Korea. “Haemoo” is based on actual events, giving sharp dimension to the story of crew members scheming, battling, and exploiting their human cargo. It has the tense, steady build of film like “Jaws,” but with a very human threat. Thriller lovers won’t want to miss this powerfully emotional drama that tightens like a winch.