The film, directed by James Marsh, stars the Oscar winning actors Colin Firth as Crowhurst and Rachel Weisz as his wife, Clare.
Crowhurst entered the 1968-69 Golden Globe Race in his 40-foot trimaran, Teignmouth Electron.
The weekend sailor hoped to win the race’s £5,000 prize money to bail out his failing business venture – selling his handheld radio direction finder called the Navicator, which allowed sailors to take bearings on marine and aviation radio beacons.
However, Crowhurst grossly underestimated his timings to prepare for the race, and left Teignmouth on 31 October 1968 – the last date he could leave under the race rules – without completing several safety features.
He soon ran into trouble and decided to secretly abandon the race, prompting him to lie about his location and to falsify logs.
His logs later suggested that Crowhurst was driven mad during the race, and his final entry – on 1 July 1969 – “It is finished. IT IS THE MERCY… I will resign the game” – inspired the film’s title.
On 10 July 1969, Teignmouth Electron was found in the Atlantic by the Royal Mail vessel, Picardy on 10 July 1969.
There was no sign of Crowhurst onboard.
The Mercy was filmed in 2015 in Teignmouth and Essex.