Blue

The film follows two friends, Lee and Kim, who serve in the Korean Navy as part of an elite diving squad specializing in emergency deep sea salvage dives. Lee is serious about his role, while Kim approaches Navy life with a more carefree attitude. Their friendship is tested when Kang, a diving instructor and Kim's former girlfriend, joins their unit, leading to a rivalry intensified by Lee's promotion over Kim.

As the plot unfolds, the dynamics between the characters shift, especially with Kim's reckless behavior putting himself and his teammates at risk. The film escalates when an incident at sea results in a submarine sinking, forcing the unit into a perilous salvage operation. The action and drama highlight the characters' struggles, making Blue a notable entry in the war genre with a unique focus on Navy divers.