Two Naval Academy deep-sea diving cadets both fall for Su-Jin, an attractive and ambitious Naval officer. This causes a rift in the two men's friendship. The three arfe reunited in the Special Salvage Unit, an elite underwater rescue team of the Korean Navy. The awkward trio must now work together and survive the treacherous situations of their life-threatening mission - rescue the crew of a submarine that is stranded 1000 feet below the surface of the unforgiving ocean. Full of suspense and amazing special effects, Blue is a taut, action-packed drama that will have you on the edge of your seat!