Maybe James Cameron should consider making only silent movies.

This week's "Sanctum" was directed by Alister Grierson and co-written by John Garvin and Andrew Wight, but you'd never know it. Cameron gets top billing, and the movie bears what have become the Cameron trademarks: stunning visuals and stupid writing.

"Sanctum" is based on something Wight lived through personally. He was part of a group of cave divers and explorers who had to fight for survival when a massive storm blew into the area and flooded the cave. The real story sounds like a great man-versus-nature scenario that needed very little embellishment.

Cameron clearly wielded great influence over the writing, though, because the movie deviates from the true story in the most ridiculous, forced ways.

This radically fictionalized tale is built around gruff, renowned Australian explorer Frank, played by a growling and scowling Richard Roxburgh, and his teenage son Josh (Rhys Wakefield), who couldn't care less about all this caving stuff.

Frank is leading an expedition financed by Carl (Ioan Gruffudd), a crass billionaire type with all the depth of a cardboard cutout. Carl brings along his girlfriend, Victoria (Alice Parkinson), so that later we can see her in her bra and panties. It's her key contribution to the expedition and to the film.

There are a few other characters in the film, but let's not bother naming them since they aren't around for long.

The mission is to explore a massive, beautiful cave system in the South Pacific, one of the last completely unexplored sites on Earth. Frank and company rappel down into the big rip in the planet and seek its outlet into the sea on the other end of the cave.

The caves are the best part of the film by far. Cameron's cinematographers and effects editors piece together a genuinely stunning landscape, all of which exists within the Earth's crust.

Unfortunately, the storm blows in and traps the crew deep within the caves, and now finding the end of the cave is the only way they can survive.

The caves, however, turn out to be much less dangerous than the characters themselves. They bicker, they make stupid decisions, they bicker some more. And every so often they decide that someone is injured too badly to go on, so they mercy kill the character.

There's just no putting it gently. The writing in Cameron's movies is stupid. His entire career has become a mind-boggling contradiction. He invests more time and money into the look of his movies than any other filmmaker, yet each script seems like it was written during lunch on set. This in turn makes him possibly the most frustrating filmmaker in history.

Speaking of the visuals, "Sanctum" uses the same 3D camera as "Avatar," which, along with Cameron's name, is a focal point of the publicity for the film. The scenery itself is breathtaking, and the crew does an admirable job of photographing and/or simulating tight spaces and a unique terrain. The underwater sequences are also impressive.

The 3D, though, rarely enhances what we're seeing. Even though I loathed the writing in "Avatar," I actually recommended that people see it in theaters because it was worth the admission price to see the 3D effects. That's not the case for "Sanctum." Add it to the ever-growing list of movies not worth the 3D premium.

All of the action sequences are at least watchable. A few are actually suspenseful. Still others provoke squirms. If you're in need of a mild adrenaline rush, maybe you'll enjoy "Sanctum."

Just be ready to plug your ears every time the characters speak.

Jeff Marker is a media studies professor at Gainesville State College.