I'm a sucker for these kind of spectacles & was easily impressed by the sight of a huge cod fish appearing to float just inches in front of my nose. Apart from the wonder of 3D, though, this movie is a pretty thin affair. It's a travelogue through undersea environments in New Guinea & Southern Australia, with no particular story line or emphasis, other than a dilute message about the endangerment of these ecosystems by global warming. The movie is no more than 45 minutes, so even the $13 matinee is an over-priced experience.
Still, the natural world has amazing visuals: a seat turtle dining on a jellyfish, a school of catfish that seems to cascade across the sea floor, sinuously swimming sea snakes, puppy-like sea lions. Even though the movie is rated G, there is explicit footage of cuttlefish sexual activity, including multiple matings & transvesticism.