Greg McLean took the Weinstein's $25m and made Rogue, a Disney ride-like monster movie that was as scary as a teddy bear's picnic. With far less money, no big names, no sweeping locations and a crew that wouldn't fill Rogue's catering truck, writer/directors Nerlich and Traucki have created a much more affecting movie.

A better movie? No, this is not a good movie. Nothing that makes you feel this terrified, that saws your nerves and puts people in the way of such fear and harm can strictly be termed 'good'. You'll be as upset after watching it as you will after watching any documentary about man's inhumanity to man.

Three holiday-makers travel to the same top end as McLean's monster (filmed in the mangroves of Sydney's Georges River) and take a similar boat trip as a fishing tour guide takes them up river into the similar territory of a hungry prior tenant.

Turning the boat over and taking the guide, the three terrified survivors are left to scramble up a tree for safety. What follows is a simple episodic story of schemes and plans to get away that meet with varying degrees of success.

But the differences between this and every other Jaws -inspired monster mash are legion. The performances suck you into these people's lives, their desperation at wanting to be anywhere else. You can almost smell their fear.

The use of real crocs as stand-ins for CGI or animatronic puppets is just as effective, and the croc thrusting itself out of the water to strike at heroine Diana Glenn as she crawls across a high branch over the water is more terrifying than a million CG crocs tearing victims in half.

It's not an adventure film, it's a horror movie in the truest sense of the word, and you've got no idea how much the realism will crawl under your skin and stay with you. If you don't like to watch suffering, steer well clear.