NEW YORK • Aquaman is an improbable movie, which in many ways makes James Wan the ideal person to direct it.

The latest chapter in the Warner Bros series based on DC comic-book superheroes, Aquaman provides an origin story for this much-maligned undersea adventurer (played by Jason Momoa of Game Of Thrones) as he teams up with Mera (Amber Heard) against the nefarious Orm (Patrick Wilson) for control of Atlantis, with Nicole Kidman playing Aquaman's mother.

Wan, 41, a spirited, quick-talking film-maker with a plume of reddish-purple dye in his hair, is used to being an underdog. Born in Malaysia and raised in Australia, he found early success with his genre-redefining 2004 horror feature, Saw.

But he struggled for years to find a worthy follow-up before re-establishing himself with hit supernatural thrillers like Insidious (2010) and The Conjuring (2013). That led him to mainstream Hollywood blockbusters like Furious 7 (2015) and finally to Aquaman.

On a recent visit to New York, he spoke about the unusual trajectory that brought him to Atlantis and the unexpected pressure now on the film.

Aquaman is a well-known superhero, if not a widely respected one. His powers - swimming fast, talking to fish - surely pale next to Superman's. Was he important to you, growing up? I did grow up reading comic books, but his books weren't the ones I read. Later, as I got older, it became apparent that people out there were making fun of him.

Sure, he was somewhat disrespected and made the joke of the superhero world. But I always found him endearing.

How did the movie first become a possibility for you? Having made The Conjuring, I was part of the Warner Bros family and I knew they were doing their DC thing.

I spoke with Kevin Tsujihara (Warner Bros chairman and chief executive) at a premiere and I said: "I'm interested in the properties that you have at DC."

A few months later, I was in a general meeting with DC and they floated two properties that didn't have film-makers on board: the Flash and Aquaman. Why did you choose Aquaman? I felt the Flash had been done before. It had been on TV twice at that point. The one that had not been done was Aquaman. I realised, wow, his character resides in this crazy, big world and I could do something very interesting with it.

I look up to people like (Steven) Spielberg, (James) Cameron, (George) Lucas, John Carpenter. I'm a fan of genre film-making, naturally. So I thought I could make Aquaman a genre film, meaning a horror monster movie.

DC basically said, yes, you can make Aquaman versus sea monsters if that's what you want.

Aquaman is obviously a piece of a larger franchise. Did you still feel you were able to put your stamp on it? It's pretty crazy. For as big a movie as Aquaman is, I could not have had more freedom.

I had all the big tools and the budget to paint on a really big canvas, but with the freedom I had on, let's say, Saw or Insidious.

So if the movie works, or doesn't work, I have no one to blame but myself.

Did you have any say in the casting of Momoa and Heard, who were introduced in previous DC movies? Even though Zack (Snyder) was making Justice League (2017), I was kept in the loop by DC and Warner Bros, and they really wanted my input on the two leads.

The great thing about casting Jason is any jokey perception that people have of Aquaman goes right out the window.

He completely nullifies any disrespect that people have for this character. Everybody knows how tough and strong Jason is. I wanted to show people the more light-hearted side of him, the goofy side of him.

I worked very hard to pull it out of him and Jason would be the first to say that I took him out of his comfort zone, quite a few times.

It is no secret that, though they were commercially successful, DC films like Justice League, Suicide Squad (2016) and Batman V Superman: Dawn Of Justice (2016) were creative and critical disappointments. Did that response affect your approach to Aquaman? I was definitely aware of that. The irony is, I picked Aquaman because I thought, here's a superhero I can make that is fully under the radar. No one's going to (care) about this film. I can just do whatever I want.

Make it easy with no pressure. Fast-forward to three years later and now there's a massive spotlight on it.

So, to answer your question, obviously there was a sense of pressure. But I try not to let any of that cloud my vision for the film. I just plough ahead and continue to make the movie I wanted to make.

You're one of very few non-white directors who've been able to make a studio movie at this scale. What's needed to ensure that other film-makers from diverse backgrounds get these opportunities? I think the willingness to take chances on different kinds of films and film-makers.

I never thought, for the life of me, that I would ever see a movie like Crazy Rich Asians, where the cast is Asian, and for the movie to do well and be well-received, it's incredible.

It starts at the top, the willingness to reach out to these film-makers and take chances.

I get it - when you're making a movie that's really big and expensive, they want film-makers that have proven track records. But there's really no excuses for not looking at more diverse film-makers.

NYTIMES

• Aquaman is showing in cinemas.