Tidal Wave, also known as Haeundae, is a South Korean disaster film released in 2009. The movie revolves around four characters - Man-sik, a divorced father struggling to re-establish a relationship with his daughter; Yeon-hee, a spa worker who is frightened of water due to a past incident; Dr. Kim, a scientist who warns about a possible mega-tsunami at Haeundae; and Hyoung-sik, a lifeguard who tries to save a woman from drowning.
The film begins with a typical summer day in Haeundae, a beautiful beach town in South Korea. The locals and tourists are enjoying the sun, sand, and sea. However, Dr. Kim, a renowned oceanographer, predicts that a massive earthquake will trigger a mega-tsunami that will devastate the area. Despite his persistent warnings, the authorities refuse to take him seriously.
Meanwhile, the characters' personal lives are in shambles. Man-sik struggles to win back his daughter's affections, while Yeon-hee is haunted by a traumatic experience in the sea. As the day progresses, Hyeong-sik rescues a woman, who he later discovers is a divorcee on her way to visit her son. The two develop a bond, and Hyeong-sik vows to take her safely to her destination.
However, as the afternoon progresses, the mega-tsunami predicted by Dr. Kim strikes, leaving the town in chaos. The characters must survive the disaster and reach safety, confronting their personal demons along the way. The tsunami destroys buildings, sweeps away cars, and drowns hundreds of people. Friends and families get separated, and everyone is left to fight for their lives.
In the end, the tsunami symbolizes the conflicts that the characters struggled with initially. The aftermath shows the couples coming together, stronger than before, having overcome their past wounds and personal struggles. Tidal Wave received appreciation for its visual effects and was a commercial success at the box office.