Earl Lynn Nelson’s voice comes rolling down the phone line from Ashland, Kentucky, all gravel and sunshine. It’s the same big voice, the same swirling Appalachian accent, that runs throughout Land Ho!, a warm-hearted buddy movie that marks Nelson’s unique debut as a leading man.

The film itself is something rare enough: how many adventure-comedies are fronted by a pair of characters well past retirement age, one of them a soft-spoken Australian, the other a pot-smoking, skirt-chasing bon vivant from the American South? And of those, how many are set in Iceland?

But Nelson’s performance is rarer still. At the age of 72, he’s only four years into his acting career—he’s not a trained actor at all, but rather an oculoplastic surgeon by profession. He just happens to be a cousin of filmmaker Martha Stephens, who wrote and directed Land Ho! alongside Aaron Katz, and who has cast him in two previous projects. The larger-than-life Nelson is a natural, it seems, even when he’s in almost every shot of a feature, as he is here.

“You talk to a lot of directors and they say that you get somebody to walk across a room, and then you put the camera on and they don’t walk the same,” he tells the Straight. “But they’ve all told me that, camera rolling or not rolling, I was the same person. So I guess maybe I’m lucky on being that way. But I’ve gotten a lot more respect for actors after being in a couple movies. You know the scenes where they shoot from one direction versus another direction, and you have to remember to say the same damn words maybe 25 or 30 times? It’s not all this fun and games and notoriety, you know?”

Among the veterans he respects most is his Land Ho! costar, Paul Eenhoorn, playing a downcast former banker pulled into a tour of Icelandic spas by his good-timin’ brother-in-law, who thinks he needs to “grab a handful of guts” and reconnect with life. An odd-couple friendship gradually blooms—which is only natural, according to Nelson, given the rapport he and Eenhoorn found soon after meeting.

“When Martha called me up and asked me if I’d go to Iceland for a month, I said, ‘Hell yeah, just hook me up, I’ll go,’ ” he recalls. “And then Aaron and Martha had seen Paul in a couple of things, and called Paul up and asked him. And they flew him to Kentucky, and they stayed here at my house for the weekend. I introduced him to moonshine out of a Mason jar and I introduced him to drinking tequila out of a bottle. The first time we met was the night before we shot the scenes that we did in Kentucky, the first of the movie.”

Still, despite Nelson’s ease in slipping into character, there’s little chance he’ll be going Hollywood anytime soon. “I’ve had people ask me would I like to be in the movie business, and I said, well, I wouldn’t mind it, but I’m not going to be going all over the country to audition for parts and so forth,” he says. “I mean, when I hang up with you I’m going to go meet a couple of my buddies and have a couple of Patróns and eat a cheeseburger, you know?”