The event in question is the Sunday Times Golden Globes Race. During the cold war, the U.K. regained a fascination with sea voyage not seen since Elizabethan days. In 1968, inspired by Francis Chichester's feat of sailing around the world, sailing enthusiasts and newspapers alike decided to promote the next biggest feat; circumlocution without ever stopping on land.
It was a tall order even for the most accomplished of sailors. And Donald Crowhurst, who signed up to take part, was decidedly an amateur. However the cash prize was a strong incentive to a man with a failing business, so he opted to sign up. From the start the media took a great interest in this unknown, dark horse contestant, trying to paint him as a symbol of British fortitude and ingenuity. Things were a bit less rosy in actuality. Crowhurst's yacht was shoddily made and his financier put severe qualifications on his funding; if Crowhurst crashed or gave up early he would have to pay for the cost of the boat. Losing would leave him in even worse financial straits. As someone who had lived in poverty during childhood, he did not want to put his family through that.
In the late 60s, with the space race going at full tilt, it was easy to feel excited about travel and adventure. However, the ocean is a vast, overwhelming place, and we've explored less than 5% of it. And, as Deep Water constantly asserts, technology was limited. During this seafaring contest, it was easy to go weeks upon weeks without human contact at all. If you bring worries and concerns with you into your sequestered existence, the demanding conditions often amplifies them to the point of it being unbearable.
Therefore, without spoiling too much, I will say that this film is ultimately a dissection of Crowhurst's failure. Deep Water demonstrates how numerous disastrous choices and coincidences lined up to create a near insurmountable situation. Even as many talking heads beat themselves up for their failure to step in, the film gently suggests that Crowhurst was running face first into economic realities, cultural expectations, and his own inner demons. There was very little that any one person could do once the ball began rolling.
That this was supposed to be a reflection on parables- both personal and nationalistic- becomes underlined in the last segment of the film. Crowhurst's son recounts his feelings upon receiving dreadful news, and how, as a child, he thought that "this is the wrong story. This is not what it's supposed to be happening."
At this point I realized that the whole documentary had been about this; people and the stories they tell (or don't tell.)
It's about people and the stories they choose to believe in, until they can't believe in them anymore.