GROTON, Conn. -- A packed audience of more than 1,300 sailors and their family members in the Dealey Center Theater at the Naval Submarine Base applauded and cheered as actor Gerard Butler and Donovan Marsh, the director of "Hunter Killer," walked onto the stage Saturday.

They were gathered at the theater to watch an advance screening of the upcoming submarine film with the actor and director, who spent the day at the base.

"It's been a joy to make, and really it's a testament to what you guys do every day, the unseen and unspoken heroes, so I hope you get that out of the movie," said Butler, who stars as a submarine captain in the film.

Butler added that they were going to watch the movie with the service members, because he "can't think of any better place to watch it than with the guys who it's actually about."

Butler and Marsh's schedule for the day included having lunch at Cross Hall Galley, attending the Battenberg Cup presentation to the USS Hartford crew, touring the USS Hartford, signing autographs for sailors and then watching the movie with them.

The film tells the story of a submarine captain who "is on the hunt for a U.S. sub in distress when he discovers a secret Russian coup is in the offing, threatening to dismantle the world order. With crew and country on the line, Capt. Joe Glass must now assemble an elite group of Navy SEALs to rescue the kidnapped Russian president and sneak through enemy waters to stop WWIII," according to a description on the movie's website. The film will be released in theaters on Oct. 26.

Ryan Gieleghem, lieutenant commander with the U.S. Navy, who watched the movie on Saturday, said he's excited that Hollywood chose to portray the Submarine Force, and the movie is good exposure for the Navy.

"We're the silent service, so not everyone gets to see the work we do," he said.

Christian Beisel, executive officer of the naval base, called the movie "fantastic" and noted that it represents a more modern-day view of the Submarine Force, since a lot has changed since the last major submarine movie, "U-571," which was released in 2000.

"It gives a current source of pride for submariners," Beisel said.

Sam Vogt, who is about to graduate from the Naval Submarine School, said he wanted to see the film because he enjoys submarine movies, and the more and more he read, the more impressed he was that Butler actually went on a submarine and "did his homework," so to speak. To get ready to star in the movie, Butler spent three days aboard the USS Houston, a Los Angeles-class sub, The Military Times reported.

After the screening, Butler and Marsh answered questions from the audience that ranged from what was it like to sleep on a submarine to what was their favorite part of being on a submarine.

During the question-and-answer session, a wife of a sailor said that in the 10 years she has been married, she's sat through every submarine movie as her husband tried to explain his job. She said they "did a wonderful job" on the film.

Marsh said that when he went to the submarine USS Annapolis, some of the crew said they're so excited about the movie because they can bring their children to show them what they do for a living and the risks they're prepared to take for the country.

Shannon Dawkins, who saw the movie with a group of fellow students at the Naval Undersea Medical Institute who are training to be Independent Duty Corpsmen, or medical providers on submarines, said she was on the edge of her seat throughout the screening.

She said that when she saw a woman in the movie trailer, she knew she had to go see the film.

"I'm the fifth female to go [through the full training at the Naval Undersea Medical Institute], so it's exciting," she said.

The Navy has been actively working with the producers and crew since December 2014, said Cmdr. Sarah Self-Kyler, public affairs officer with the U.S. Submarine Force.

"We wanted to ensure submariners were the first to view the movie," she said of the advanced screening in Groton.

"It's been wonderful to host the cast and crew of 'Hunter Killer,'" she added. "Their appreciation for the Submarine Force is obvious in all their interactions with the sailors today."