LOS ANGELES — In “The Finest Hours” (opening Friday), Chris Pine portrays Bernie Webber, a young Coast Guard officer in 1952 who spearheaded the rescue of merchant marine sailors from a oil tanker that had been split in two — and was in the process of sinking — in a horrible nor’easter storm off the coast of Cape Cod, Massachusetts.

The actor said a recent water trip made him realize exactly how dangerous that rescue mission was in the middle of the last century.

“I was in a boat that had to take me from the place where I had been on vacation to the airport, to fly home. We were in 25-foot waves, the sky was extremely dark and, to be frank, it was terrifying.

“So I can’t imagine what those gentlemen went through in a 35-foot wooden boat — facing 70-foot waves, without a compass, in snow and sleet and in pitch darkness!

“Thank God there are braver men than me in the world who will risk their lives in situations like this. That’s what I call true heroism.”

Because the real Bernie Webber has been dead for a number of years, Pine was not able to meet him and hear from him firsthand about that now-famous rescue mission. Yet, even if he had, the actor doubted he would have learned much.

“I’m highly cognizant of the fact Bernie didn’t like speaking about it. In fact, I’ve learned all of the men involved in that mission similarly didn’t dwell on it either. The wife of Andy Fitzgerald [played by Kyle Gallner in the film], who was on the boat, didn’t know about it until two years after they got married! You know what Andy’s rationale for that was? He said, ‘Because no one ever asked me about it.’

“As for Bernie himself, I read an interview he gave in the mid-1960s. You could just tell, he seemed so bored, so reticent to discuss this. … That was the defining virtue of these men. It was all about doing the job for the sake of doing it. They were not interested in any kind of congratulations. It was all about being as selfless as was humanly possible.

“We certainly need more men and women in our world like that today.”

Joining him is Casey Affleck as Ray Sybert, the oil tanker’s reclusive chief engineer. The role required him to be constantly covered with grime and sweat — portraying a character whose entire professional life was spent well below the decks of the ship.

“I’d get home after a long day of shooting and the first thing I’d do is get in a long, hot shower,” said Affleck with a chuckle.

The Boston native had a number of reasons for agreeing to sign on to “The Finest Hours.”

“One, it was a great story that I felt a lot of people needed to know about. Secondly, it was something I could do that my kids could finally see! Third, I love movies that are set in Massachusetts — plus I love period movies.”

Since he was a kid, Affleck has spent a lot of time on Cape Cod, so he was very familiar with the locations where the film was set and shot. “It really felt like you were in 1952 Cape Cod. Sometimes, even if I wasn’t needed on set, I’d show up and just sit there and look around and take it all in. It stirred nostalgia for me in a big way.”