Steve Irwin, the Australian zookeeper and wildlife activist whose Crocodile Hunter shows have made him a hit on The Animal Planet in America and television networks around the world, makes an easy transition to the big screen in this feature constructed by his long-time collaborator John Stainton. That’s because in the scenario concocted by Holly Goldberg Sloan from Stainton’s concept, Irwin and his wife Terri don’t have to act at all: essentially they play themselves, repeating the direct-to-the-camera shtick familiar from their TV fare as they travel about the countryside Down Under and interact with all sorts of critters along the way. These segments, which account for more that half of the movie, are shot in the same no-frills, small- screen format characteristic of the small-screen shows. But interspersed with them is a second plot line, running along a parallel track but shot in wide-screen, in which a trio of American intelligence agents are trying to track down a satellite gizmo that’s been swallowed by a croc that Irwin has been engaged to capture and transport to an area removed from the homestead of an irate rancher. The joke is that when the stories intersect toward the close, Irwin assumes that the agents are poachers who aim to kill the croc and does all he can to foil them.

By any objective standard “The Crocodile Hunter: Collision Course” is a terrible picture, chintzily made and amateurishly executed, but it will probably satisfy die-hard fans, simply because it allows Irwin to do precisely what they like–cuddle kangaroos, wrestle crocodiles, play with spiders and lizards and grab snakes by the tail (if snakes can be said to have tails, that is)– all while discoursing on the importance of protecting wildlife in his customarily ebullient, even manic style. Youngsters in particular seem to take to his act, and if he succeeds in implanting a healthy respect for the natural world in some of them, he’s clearly doing good work. His wife makes an amiable partner for him, too; she’s as comfortable before the camera as he seems to be. If you or your children are devotees, you needn’t hesitate.

Still, it has to be pointed out that the rest of the flick is pretty awful stuff. The whole spy business is silly, but even worse it’s ineptly constructed and staged. There’s supposed to be some interagency rivalry at work, but the details are pretty much incomprehensible, and the actors involved–Lachy Hulme, Aden Young, Kenneth Ransom, Kate Beahan, Steve Bastoni–are all dull as dishwater; most of the action surrounding them is simply humiliating rather than funny. Nor is the supposedly humorous characterization of the rancher angered by the crocodile killing her cattle at all successful. As played by the talented Magda Szubanski (Mrs. Hoggett in both “Babe” flicks), Brozzie Drewett, as she’s called, is just a scowling obese woman who endures a succession of unpleasant slapstick indignities. In fact, the only professional performer who comes through unscathed is David Wenham (“Better Than Sex”), who shows an understated charm as a local policeman.

Even technically “Crocodile Hunter” disappoints. One might have thought that the vast Australian expanses would have drawn remarkable work from cinematographer David Burr, but the movie has a washed-out appearance that doesn’t do any justice to the locales, and overall the production looks decidedly threadbare. The verdict? If you’re an Irwin fan who wants to see your hero on the big screen, here’s your opportunity. Everyone else will have a very difficult time understanding what all the fuss is about.