In “Nyad,” there are two feats of perseverance on display. First, there is the ceaseless determination of Diana Nyad (Annette Bening) to accomplish a marathon swim from Cuba to Florida across 103 miles of open, shark-infested waters. Then there is the mettle of Nyad’s support team to tolerate the singularly self-absorbed and stubborn Nyad. Both, in the film, are an endurance sport.
“Nyad,” which opens in limited theaters Friday and streams Nov.
