“Oh Lord,” the old fisherman’s prayer goes, “Thy sea is so great and my boat is so small.”
Anybody who has ever sailed a boat — any boat — over the wine dark sea has that line at the ready for those inevitable moments when hopeless peril is at hand.
The old sailor (Robert Redford) doesn’t say it aloud, but you wonder if it crosses his mind as his boat, his gear, his body and his luck fail him. He doesn’t say much of anything, just a certain well-played swear word that sums up everything that happens to him in “All Is Lost.” Considering that moment, no one will blame him.
“All is Lost” is “Gravity at Sea,” a brilliantly spare film about the hazardous inner journey that tests one old man’s intestinal fortitude and his resourcefulness to the max as his small sailboat is disabled in the middle of the Indian Ocean.
“I tried to be true,” he says when we meet him. “I tried to be right. But I wasn’t. I’m sorry.”
He’s writing a farewell note to those he left on shore. We don’t see them or meet them and we don’t even know this old mariner’s name. But Redford, in a compact, tour de force performance, tells us all we need to know just with his reasoning, his competence and those moments hi competence comes up short.
His small sailing sloop — a 35 footer, from the looks of her — collides with a loose shipping container full of sneakers and the hull is stove in.  Our sailor has to gather his wits, free the boat from the container, patch the flooded hull and pump it out. He needs to rinse and dry out his electronics, which tell him where he is and with which he could tell the world he’s in trouble. He needs to find land, or help, using skills — navigating by the stars — he never bothered to learn.
From the floating shipping container collision on down, these are all familiar tropes in the modern lost at sea saga. They’re the ingredients of a thousand contemporary cruising sailor tales, people used to modern devices forced to rely on everything they know — which might not be much —  when the modern stuff fails.
Writer-director J.C. Chandor (“Margin Call”) switches gears with this intimate story of silences and severe tests at sea. Yes, there’s a storm. Yes, there are sharks. And yes, gigantic, under-crewed and inattentive container ships like the Maersk Alabama of “Captain Phillips” play a role.
Chandor provides Redford with a grueling, Oscar-worthy role in a story told in a long “eight days earlier” flashback, sending the 77 year old actor up the mast (clever camera placement) and under the waves, nearly drowning time and again as he tries to save first his boat and them himself.
And Redford isn’t shy about letting us see his age. Pulling yourself up a mast in a bosun’s chair could exhaust a 30 year-old, and whatever makeup might hide in the fresh air is exaggerated under water. We see every bloodied, cracked crevasse lining his face and root for him to rage, rage against the dying of the light. Or to at least catch his breath.
You don’t have to be a sailor to appreciate Chandor’s skill in creating a character who is no “old salt,” but a fellow who quite probably took this late ’70s vintage boat to sea as a late-life hobby, a man forever reacting, slowly, a step or two behind the ills that befall him. You see storm clouds, you furl or reef the sails. Your boat is damaged, you don’t go below decks to ride out that storm in denial.
This solo ordeal won’t be to every taste, but “All Is Lost” is a grand vehicle for the actor and for that viewer ready to consider his or her own mortality, the problems, conflicts, strengths and shortcomings you’re sure you leave behind when you just sail away. As it turns out, you don’t.

(Roger Moore’s interviews with Robert Redford and J.C. Chandor are here).

MPAA Rating: PG-13 for brief strong language
Cast: Robert Redford
Credits: Written and directed by J.C. Chandor. A Roadside Attractions/Lionsgate release.
Running time: 1:45