Hit filmmaker Ryoo Seung-wan’s upcoming action crime flick “Smugglers” begins with a small boat sailing through a peaceful seaside town called Guncheon.

The 130-minute movie quickly unfolds, showing how a group of “haenyeo,” female divers who collect seafood from the ocean floor, become involved in illegal smuggling to make ends meet.

Jo Choon-ja (Kim Hye-soo), who secretly escapes the crime scene, returns to the old town three years later. Her best buddy Um Jin-sook (Yum Jung-ah), who had spent time in prison on a smuggling charge in the meantime, feels betrayed when Choon-ja reappears.

But they soon resolve the misunderstanding to collaborate for a mutual goal, clearing hurdles like Mr. Kwon (Zo In-sung) and Jangdori (Park Jung-min).

As the film jumps back and forth in time, dealing with various characters’ differing interests, the plotline is never dull, but also not too hectic. The movie offers a joyful, rhythmic ride throughout its running time, with the fun melody of Korean folk music from the 1970s.

In an underwater encounter between the haenyo and a gang, unprecedented, physics-defying in-water action sequences show a real vividness. With the sounds of water, backflipping haenyo freely cleaving through the water to deliver a punch to the face or fling an octopus at an enemy is just the experience to chill out inside the cinema on a scorching summer day.

Kim Hye-soo, who vigorously leads the female-led blockbuster as Choon-ja, said she did not believe at first how the in-water action scenes could be possible. In the film, her character is so powerful and memorable that it could be career-defining, at least after Madam Jung in smash-hit heist flick “Tazza: The High Rollers” (2006).

“It was fun to just hear the keywords of the movie – haenyo, smuggling, 1970s – and I decided to do this project,” Kim told The Korea Herald in an interview in Seoul on Wednesday.

“At the very first meeting with director Ryoo, he showed me footage of haenyo underwater and that made me feel dizzy. After shooting ‘The Thieves,’ where I was locked inside a submerging car, I think I began to be afraid of the water. But overcoming such fear, I’m just so thrilled to see the phenomenal underwater action we did as a team,” Kim said.

Because she had to join “Smugglers” belatedly as she was still shooting TV drama “Juvenile Justice” in 2021, Kim said she wanted to prepare beforehand as much as she could by researching and collecting data on the 1970s.

“I’m personally very fascinated by the fashion, hairstyles and music from the 1950s to 1970s. The matching red-striped two-piece suits that Choonja and Jin-sook wear in the movie were my idea,” said Kim, adding she apologized to the art team for sending too many references. “They first liked it, but later they wouldn’t reply back,” she joked.

“But that was my way of preparation to get into the project. Choon-ja was a character of desire for me,” Kim added.

Among four domestic blockbusters opening this summer, “Smugglers” is the only film putting two female characters at the fore. It remains rare to see Korean female-led blockbusters in local cinemas with a budget of over 10 billion won ($7.9 million).

But Kim said she doesn’t see “Smugglers” just as a film led by female actors.

“For me, my responsibility is to perform what I’ve promised to do between myself as an actor and the director. Other than that, I do not know. I’m just not capable enough to think beyond that. For me, this film is great not because it was a female-led blockbuster, but a film that vividly shows the relationships between lively characters and a great ensemble between actors. I don’t want to define our film other than a film of various characters,” said Kim. “That’s it.”

“Smugglers” hits local theaters July 26.