20 Documentary Movies You Must See Before You Die

8. The Cove (2009)

Positioned as a heist movie of sorts, The Cove is remarkable and gripping documentary that chronicles a crack squad of activists who set out to expose a secluded cove in Japan where - every year - hundreds of dolphins are lured and brutally murdered.

Directed by Louie Psihoyos and featuring Ric O'Barry, a former dolphin trainer who turned against the industry and became an activist, as the team's leader, much of The Cove is dedicated to an intricate mission to plant secret cameras in the film's titular location. As the Japanese attempt to thwart Barry and his gang, they are forced into covert ops mode and must conduct their business at night using stealth and state of the art equipment.

But is the later scenes of the dolphins actually being killed - and the shots of the water as it changes colour from blue to a vibrant red - that will truly haunt you in the aftermath.

The Cove became a majorly controversial film, especially in Japan where it was deemed to be a one-sided affair. However you view the situation, watching the film it's impossible not to see real terror unfolding in the dolphin's eyes as they're captured and slain.