Who's In It: Pierce Brosnan, narrator
The Basics: Look at those turtle babies! Oops, some got eaten by birds. Well, okay, look at those whales feeding on krill. And a lot of octopi and penguins (of course) and crabs and eels and more freaky blobby science-fiction creatures than the movie can even list or tell you about. Look at it all! It's awesome! It's the kind of movie that the guys from Insane Clown Posse probably watched before writing that dumb new song of theirs about how baffling nature is and how they can't figure out magnets.
What's The Deal: Finally we have cameras sophisticated enough to really get up close and show you all the weird details of the million mysterious citizens that live miles underwater. And it's not like you're ever going to go down that deep yourself, so a film like this is guaranteed to show you about three dozen things that will blow your mind. That's the hi-def newness part. The old-school appeal is that it's a perfect family movie. There's no plot for the littlest ones to try to follow or get bored by, and it's strange enough to hold the attention of older kids. And for their parents, it'll be a nice trigger for their memories of watching old nature shows on Wonderful World of Disney.
Where It Comes From: Jacques Cluzaud and Jacques Perrin, the men behind the flabbergastingly beautiful bird doc Winged Migration. This is another one that'll make you go, "How did they get that shot?" because it's as if they're aiming the cameras straight up the noses (or ventricles or whatever) of these animals. And because these guys are serious about their work, the movie has much less anthropomorphic silliness than a lot of projects that care more about making you say, "Aww" than making you feel awe.
Stuff You Won't See In America: The original French version of this movie is about 15 minutes longer and features one of the filmmakers and his grandson talking about the importance of preserving and respecting other species and their habitats. That stuff is mostly gone here. The other contentious scene involved a simulated shark mutilation by fishermen eager to get the fins for restaurants.
Best Part: The mantis shrimp. It's bizarre looking and it fights with pretty much everybody. (It is, in fact, more exciting to watch this thing fight than it is to watch most action movies.) And it doesn't back down. So in case you happen to be down in the darkest part of the sea someday, remember that you don't want to tussle with a mantis shrimp.