The Real Story Behind 10 "Based On A True Story" Horror Films

4. Open Water

The pitch: This micro-budget 2003 marine thriller in which frustrated married couple Daniel Travis and Blanchard Ryan end up abandoned in the open sea on a scuba diving trip before being menaced by sharks had its intimate indie feel of authenticity buoyed by the notion that it was based on the same thing happening to real divers. The real story: Diving enthusiast writer-director and producer team, husband and wife Christ Kentis and Laura Lau, based their story on the real case of Peace Corps volunteers Tom and Eileen Lonergan who, in January 1998, were left adrift as part of a scuba diving trip to the Great Barrier Reef. The characters of the movie's couple Dan and Susan (Travis and Ryan) are not remotely based on those of the Lonergans, except for an interest in diving, while the Pacific location has been switched for the Atlantic, but the events of the story definitely are. Like the movie couple, the Lonergans were not collected by the boat that returned to pick up their group. Their disappearance was not noticed until much later when their bags were found in the boat and this prompted an unsuccessful search. Diving gear was eventually discovered but the fate of the divers is unclear. All of this is replicated relatively closely in the film, but the actual events while Dan and Susan are in the water (really the main body of the film) is impossible to relate to the truth as nobody will ever know what happened to the real Lonergans. The possibility that they became exhausted, dehydrated and were drowned and eaten by sharks (as happens to their movie counterparts) is fairly likely, but theories about their disappearance run to everything from an elaborately staged fake death to a murder-suicide pact.