Han Ye-ri in Shim Sung Bo's "Haemoo"

It speaks to the quality of “Haemoo” that when Shim Sung-bo reflects on what was the most difficult day of filming the technically complex high seas thriller about a fishing crew that attempts to smuggle a group of Korean immigrants back from China, it wasn’t the physical challenge of ‎shooting one of the film’s harrowing action sequences that got to the director. It was how it could be as emotionally devastating as possible that he took great pains to get right.

“The most difficult moment was the last scene because we had to shoot it earlier [than expected] because of our production schedule,” says Shim, speaking through a translator as the film made its Los Angeles premiere at the AFI Fest. “I had to make some different choices than was originally written on the scenario, [and] doing that first, without going through all the other transitional parts, was hard.”

You wouldn’t know it from the final film, which exudes a confidence from start to finish that would hardly suggest Shim was a first-time director. Then again, he’s been waiting for this opportunity for over a decade since he first made a name for himself internationally as the co-writer of Bong Joon-ho’s breakthrough sophomore feature “Memories of Murder.” To return the favor, Bong helped Shim produce “Haemoo,” which like the “Snowpiercer” director’s work combines the exhilarating highs of well-crafted action and suspense with a social consciousness that makes every twist and turn feel like a punch to the gut.

Based on a real-life incident that was originally adapted for the stage, the film posits the those traveling on the boat as a microcosm of Korean society in the wake of the economically IMF crisis of the late ’90s with every individual decision made affecting everyone else onboard, with the question of whether each passenger is acting out of self-preservation or for the general good as much as a driving force for the story as the furious waves that pound the ship and have everyone fear for their survival, particularly when it comes to a burgeoning romance between a member of the crew named Dong-sik (Yu-Chun Park) and an immigrant named Hong-mae (Ye-ri Han). Boasting an unusual two-gimbal approach to the camerawork that brings audiences right into the stormy waters, Shim creates an all-consuming experience that won’t let go either viscerally or psychologically and after being selected as South Korea’s official entry into this year’s Oscars, he spoke about how important casting was to the film, making the most of a limited setting and how he’s only just getting started.

Han Ye-ri in Shim Sung Bo's "Haemoo"How did this film come about?

Director Bong Joon-ho of recommended a stage play based on a true story, so I read it. I liked it because it was about these regular people, just like you and me, but somehow they got involved in a crime and that eventually led to their destruction, but the whole story was unfolding from their point of view. Another important theme of the play was the love story between Dong Sik and Hong-mae’s characters, so together I thought okay, I’m going to make a movie out of this.

Was this difficult to visualize since it came from a stage play?

Actually, the entire play happens in a fishing vessel, so once I thought that my film could focus on the ship, it wasn’t hard. I liked the claustrophobia of the limited setting. People were put together and ‎there was a sense of nowhere to go, so I used that element [for tension]. In the play between scenes, they also make the transitions just by using only sound and I tried to visualize that sound.

You also hired Hong Kyung-pyo, who is known for his work on the water in such films as “Typhoon.” How was he a help?

Yes, the cinematographer is a consummate craftsman, [specifically skilled in] the coloring and positioning of characters. He’s known for all of those things and for how he utilizes the smog for filming – yes, he made “Typhoon,” but he also made a film called “Ghost.” Honestly, in Korea, unlike Hollywood, we don’t accumulate a lot of technology that can deal with this type of movie, so beyond being a cinematographer, he was more like a producer. His contribution was very essential for the movie.

Park Yu-Chun and Han Ye-Ri in "Haemoo"Was it difficult to accommodate such a large cast of characters?

It wasn’t easy. I’m a new director, so dealing with all these actors wasn’t an easy job. But another thing is that a lot of my actors are well-known. They’re rather famous actors in Korea, even though some of them play the smaller roles and it was because the story unfolds in a very claustrophobic, limited space. That means a lot of the time, you have to have to focus on these characters’ subtle movements, like their facial expressions, so I wanted good actors who could handle not just the dialogue, but when I put the camera on their faces, they could show what they’re feeling.

The captain is played by Kim Yoon-Seok, who is best known for playing villains in “The Chaser” and “The Yellow Sea,” but in this film, you’re never quite sure whether he’s good or bad. Did you want to take the personas some of your actors were known for and subvert them?

First of all, I didn’t try to change his image from this well-known villain character actor to a good guy. That wasn’t it. But you’re right, Kim Yoon-Seok has played many villainous roles. However, he has played regular guys, like a father who struggles to support his family too, so he can embody both of these different characters. He can be strong and rather imposing, but also he’s an everyman, so I thought maybe in my movie is where these two types of characters he plays could intersect. Also, the guy is very sensitive, very subtle. There’s a lot of subtlety and a lot of times he can be touchy-feely, so that’s why I cast him in the role of Captain Kang.

Shim Sung Bo's "Haemoo"You’ve said a big part of Bong Joon-ho’s contribution was to help simplify things. Was there a specific thing he really helped with? [minor spoiler ahead]

You remember the boatswain [Ho-young, played by Kim Sang-ho] who holds Hong-mae from the engine room and [plans] to throw her into the sea? Originally, my idea was the boatswain was going to save her, and of course, at that moment, the captain is out of his mind. So the boatswain was going to deceive the captain, saying yes, yes, I’m going to kill her, but he was actually going to save her. But Bong Joon-ho suggested if you make the boatswain a good guy like that, that was going to be a burden for Dong-Sik later. So I decided that supporting character should be consistent. That way, I made that audience focus on Dong-sik, seeing the struggle within himself between good and evil.

After waiting patiently to make your first feature, what is it like to now be taking it around the world?

Through my film, I’ve been able to meet a lot more people than I’m used to, not just Korea, but from all over the world. Also, of course, I realize there’s still a long way to go. I know my own shortcomings, so I’m resolved to go deeper and study more. I think this is a new beginning. This is going to be my set point that will help me find my next stop to go.

“Haemoo” will be released by Film Movement later this year.