This story of survival is bizarre, inexplicable, and true. One raw night in March 1984, a fishing trawler capsized off the coast of Iceland; six men went into the water and only one survived, by swimming for five hours in temperatures that would have killed the average human inside 15 minutes.
In Baltasar Kormákur's dramatisation, Olafur Darri Olafsson plays Gulli, a pudgy, unassuming fellow who saw his shipmates drown and imagined he would. As he's carried across the roaring deep he prays, he calls to the birds, he voices his regrets. (He's mortified that his mother will have to pay his debts.)
The film shrinks his ordeal to 90-odd minutes, most of it compelling, though the end-credits insert of the actual survivor has a deflating effect. Either keep faith in it as a drama, or make a documentary. Muddling the two sells the tale short.