Diana Nyad’s epic swim from Cuba to Florida isn’t even the most astounding part of the story | Emma Brockes

Annette Bening plays the swimmer in a new Netflix biopic; but as her coach, Jodie Foster also achieves something remarkable

There is something mythic about the story of Diana Nyad, the first (and, to date, only) person to swim the 110 miles from Cuba to the US without the use of a shark cage. Nyad was 64 and on her fifth attempt when she succeeded in 2013, a feat that should not have been humanly possible. As well as the sharks, there were deadly box jellyfish, and the Gulf stream itself, threatening to sweep her away from the support boat and out into the ocean. Her success was inspiring and continues to inspire, although, as we see in Nyad, the new Netflix biopic, not always in the obvious ways.

You would have to be a maniac to attempt - and keep attempting - what Nyad did, and this is the energy brought by the actor Annette Bening to the title role. Bening's heroine is capricious, raging, solipsistic to the point of narcissism, and wholly indefatigable. At an age at which people in general and women in particular are not considered apex performers, Nyad breaks her 30-year hiatus on swimming and, for all the reasons people make radical changes at that stage of life - fear of death, fear of obsolescence, fury at the realisation that this is all going to be much shorter than anticipated - gets back in the pool. She is, per the movie, a total nightmare of a person - and also blows your mind.