The feature film debut of writer and director Jong-seok Yoon. Yoon said that he first began thinking about the story after watching a "very moving film noir", which inspired the type of characters he would later write into his script. During casting he was keen to avoid stereotypes, and for the role of Kang wanted someone who looked more like a businessman than a typical gangster boss, choosing Cho Jae-hyun for that reason.
Lead actor Kim Kang-woo had to overcome his fear of water, and prepared for his role by undergoing three months of intensive training, which began with learning basic swimming strokes in a pool and progressed to more advanced skills such as scuba diving. Kim went on to film dangerous water sequences without using a stunt double, earning praise from his fellow cast members and the production crew.
Filming commenced in Seoul on 17 May 2008 with scenes of Cheon-soo and Yu-ri's first meeting, and later moved to Cebu Island in the Philippines.
The film's production went through much trial and error due to the crew's lack of experience of filming at sea, and both crew members and actors suffered severe seasickness during filming.