Carl (Ioan Gruffudd) © 2010 Universal Studios

Ioan Gruffudd really should have known better – after all, his character, 5th Officer Harold Lowe, almost perished in James Cameron’s Titanic. But no, now he’s underwater in Cameron’s new thriller Sanctum.

In the movie Gruffudd portrays financier Carl Hurley, who is a member of a team exploring the Esa’ala Caves in the South Pacific. But when a flash flood cuts off their exit, the divers must navigate an underwater labyrinth to find a way out before it’s too late.

You’re no stranger to James Cameron’s water-bound productions, did your association with this film come before you knew what type of a film it would be, and if not are you a glutton for punishment?

Well, I survived the Titanic, you’re absolutely right. In fact, the character that I played in the film was a survivor. He was a real character that survived that horrible ordeal that evening. He was a Welshman from North Wales. So it goes to show how thorough Cameron is in his casting, he wanted a guy that came from Wales, because this character came from there.

In this circumstance the movie was directed by Alister Grierson, we mustn’t forget that. But to have Cameron there (as the Executive Producer) overseeing this as a presence throughout, obviously gave us a lot of confidence moving forward. Alister Grierson is the visionary behind this story, that has brought this to life; and Cameron is very proud to run with it, I think.

Carl goes back and forth from being good to bad, was it hard to channel that?

Josh (Rhys Wakefield), Victoria (Alice Parkinson) and Carl (Ioan Gruffudd) © 2010 Universal Studios

It’s just a pleasure as an actor, it’s just pure imagination. One doesn’t know how one would respond in these circumstances, and we see these people go from good to bad, because they are really grappling with their survival instincts and what is the right thing to do and what is the selfish thing to do?

Sadly Carl couldn’t cope in the end. He got a second chance at redeeming himself and still he wanted it all for himself. I think we’ve taken it to a whole other dimension. We’ve heightened the story that actually happened back in 1988 to these cavers in Australia, so we’re just taking it to another level, because after all it is a movie, it is a story and [the audience] wants to be thrilled, educated and entertained at the same time.

What was making this movie like for you physically?

They tried very hard to kill me on this one, but luckily I’m still here to tell the story!

In one scene you have to base jump into the mouth of a cave.

Victoria (Alice Parkinson) and Carl (Ioan Gruffudd) © 2010 Universal Studios

I was strapped to a crane and had a safety line tied to my back. But I did throw myself off a cliff and put my faith in the safety line, and I certainly did get an idea of how exciting it must be to do that for real. I free-fall for a few seconds, it’s actually me doing it in the film, so that was a big personal thrill.

And in another scene you had a pot of burning oil thrown on you.

We had to practice that a few times so I was comfortable enough with it. We had to get to the point where I was actually on fire for a couple of shots before they cut to the stunt guy. But you do see the flames in front of my eyes and that is my face behind it. So yes, I did well to survive this particular project.

How much of your screen time was you versus the stuntman?

I would hazard a guess that it was 50/50 to be honest with you. It all took place on night shoots so we could get the darkness of the sea, and it was a fantastic process.

Like these cave divers, everything was planned. We would collectively gather every evening with the director with a model of what we had underwater, of the cave environment, and little mini divers on pieces of string, and then we were shown this is where the camera is going to be, this is where you guys are going to be. Then we’d move to the car park and block it out as if we were blocking out a scene on a television set. So when we were down there we knew exactly what to do at any given time.

Do you have any idea how much time you spent underwater?

Carl (Ioan Gruffudd) © 2010 Universal Studios

It was a normal working day until the light came up.

We started first thing in the evening and then they would finish off with the stunt guys doing the wider versions, where you couldn’t necessarily see somebody’s face behind the mask.

But it is us doing it at any given time when the close-up is needed of a particular character, you can tell it’s us and it’s us underwater in this fantastic environment that the director of photography and the production designer had created for us.

What was the scariest moment on the set?

Just on a personal level, bizarrely it wasn’t the diving or throwing myself off the cliff, it was in fact doing a fight sequence with Rhys Wakefield, because emotions and intensity are high and we were actually doing it for real. We were surrounded by a body of water, Rhys’ literally trying to keep me under the water, and I was trying to struggle out of the water.

And we were exhausted, so I was constantly breathing at the wrong time, breathing whilst I was underwater. I was gasping for air. That’s fascinating, because here we are shooting a movie about the most dangerous sport in the world, but we never felt in any danger until that point, which had nothing to do with diving or being in the cave.

Judy Sloane

Judy is Film Review Online's regular Los Angeles based reporter. More by Judy Sloane