The anaconda attack effects, though, are simply sensational, well worth waiting for and amply compensate for the sluggish voyage down the Amazon that precedes them.

Otherwise it's formula stuff, lifted somewhat by a wonderfully over-the-top performance from Jon Voight which completely overshadows his co-stars Jennifer Lopez and Ice Cube.

But it's the execution of the action that takes the breath away, especially one shot of the pipeline-sized anaconda swooping down on a man attempting to escape its jaws by diving off the top of a waterfall.