Joe Wein buys a lot of books, intrigued by the subject, but he doesn’t always read them from cover to cover.

But a decade or so ago the Los Angeles-based filmmaker happened to see a copy of Mainer Steven Callahan’s true-life survival story, “Adrift: Seventy-six Days Lost at Sea.” The details of how Callahan survived alone in a small life raft in the middle of the Atlantic in 1982 had Wein riveted, as both a reader and a filmmaker looking for good stories.

“It was a surprisingly amazing book. It was soulful and thoughtful, and I found it to be a metaphor for how to solve problems in life,” said Wein. “It really connected with me. It’s like being in a thriller, too, because you put  yourself in Steve’s place and think ‘What would I do?'”

Wein contacted Callahan, who lives in the Downeast town of Lamoine, and said he’d like to make a documentary about his time on the raft. The finished film, “76 Days Adrift,” will be part of this year’s Maine International Film Festival in Waterville. It will screen at 7 p.m. Thursday, July 17 at the Waterville Opera House and again on July 19 at 12:40 p.m. at the Maine Film Center. The second showing is already sold out.

The film’s executive producer is Ang Lee, the critically acclaimed director. He already knew Callahan’s story, having hired him to serve as the marine consultant for his 2012 film “Life of Pi.” That film focuses on a young man and a tiger, perhaps an imaginary one, adrift on the ocean in a small boat.

Because Callahan’s book had been a bestseller after it was published in 1986, there has been interest from filmmakers before. But Callahan did not care for the proposals he had heard about, which did not stay true enough to his story, in his opinion.

That’s why a documentary appealed to Callahan, 73, who has spent his life sailing and building boats. He has lived and built boats at his home in Lamoine, near Mount Dessert Island, since the late 1970s.

“A lot of them wanted to do a Hollywood-type drama, a movie of the week, and most of the scripts, frankly, weren’t even close to the story I told in my book,” said Callahan. “Then Joe came along and proposed the documentary, and I thought that was something I could be more comfortable with.”

Callahan was heavily involved with the film, including traveling to the island of St. Croix to help supervise shots that re-create his experiences, using a round raft very similar to the one Callahan had. Callahan, who also serves as an executive producer, narrates much of the film. There is also film footage of him on his sailboat, the Napoleon Solo, taken by friends just before his perilous solo journey.

SURVIVAL STORIES

Wein has worked for years as a writer on projects for Paramount, Fox and other studios. He served as producer and director for “76 Days Adrift.” The documentary was made as an independent production and completed before Lee signed on as an executive producer, a move that has helped get the film more attention. Lee is known for such critically acclaimed films as “Brokeback Mountain,” “Crouching Tiger, Hidden Dragon,” “The Ice Storm” and “Sense and Sensibility.”

Lee had asked Callahan to be a consultant on “Life of Pi”  largely because of Callahan’s book and the way he analyzed the minute details of his own survival. “Life of Pi,” based on a novel by Yann Martel, is about a young man whose family runs a zoo in India. While transporting some of the animals to Canada by cargo ship, it sinks, leaving Pi adrift on a small boat with the tiger.

Callahan said he jumped at the chance to work on “Life of Pi” because he’s often disappointed at how other seagoing films come out. He helped direct the waves in a giant wave tank used for most of the scenes, as part of his duties. He also helped filmmakers understand how the night sky would look and feel to someone afloat hundreds of miles from anywhere.

Though Callahan had a good experience working on “Life of Pi,” and was praised by the filmmakers, he had no idea Lee wanted to become involved with the documentary about his own experience until very late in the process.

“Steve has kept in touch with (Lee’s company) but it still seemed like a real long shot that they’d get involved,” said Wein. “But suddenly we got this email saying they really loved the film and wanted to come on board.”

Callahan grew up in Boston’s western suburbs, but began sailing out of South Shore towns in high school and become a self-described sailing “addict.” He lived on a boat for a while and worked at a variety of marine-related jobs, including building and repairing boats.

When he was 30, Callahan decided to fulfill a longtime dream by sailing across the Atlantic alone in a 21-foot sloop he had built himself, the Napoleon Solo. He had sailed from the U.S. to Europe, with a friend on board part of the way. In January 1982, he left Spain to make a solo journey back across the Atlantic.

About a week into the journey, Callahan’s 21-foot sail boat was likely struck by a whale and then sank about 450 miles west of the Canary Islands. He quickly grabbed what he could for supplies and jumped into his 6-foot-long raft, which he named Rubber Ducky.

He spent the next 76 days drifting in the Atlantic Ocean, menaced by sharks and other creatures. He survived by eating barnacles, and birds and fish that he speared. He drank whatever rainwater he could catch. When he was finally rescued by fishermen, he was severely dehydrated and weighed about 100 pounds, after losing more than a third of his body weight. He was immediately taken to a hospital on the Caribbean island of Marie-Galante.

After his rescue, Callahan spent years working as a ship designer, as well as a survival and safety consultant.

Wein said he began the film by traveling to Lamoine to record interviews with Callahan. He ended up with about 25 hours of detailed interviews, which was used as narration in the film. Then Callahan went with the crew to St. Croix, in the Caribbean, to film recreated scenes. For many of those, the camera is in the raft looking out, to give the audience Callahan’s point of view. The film explains and recreates how Callahan caught food, tried to plug holes in the raft, and created a sextant out of pencils to try and figure out his position by observing the stars in the sky.

The music in the film was composed by Patrick Stump, lead singer and songwriter for the rock band Fall Out Boy.

Callahan said working on the film, looking through his old log books and revisiting his time in the raft, brought “a lot of things back to me in a very visceral way,” even though he’d already talked about his experiences quite a bit over the years, as well as writing a book.

The movie premiered at the Santa Barbara International Film Festival in California in February 2024 and has been screened at several New England venues, including the Peabody Essex Museum in Salem, Massachusetts, in June. It will also play at the Strand Theatre in Rockland on Aug. 24 and at the Milbridge Theatre, though that date has not been set.

“I’ve been very fortunate because I got to turn this thing into a positive, which is gratifying,” said Callahan. “But it is hard living with it all these years.”