Deep Blue

From the explosive beginning, fighter sharks zoom like supersonic aircraft through shoals of fish that gracefully and miraculously reform again and again in tight protective circles. Killer whales show their prowess at poaching baby seals, throwing them high, spinning and struggling through the air. Babysnatching in such shallow waters runs the risk of being beached. Natural justice, I would say. The music is impressively fierce, the screen too close.

Jazz, Cuban-style, gives comic relief, as millions of crab-like creatures - armies on the move again - shimmy across a vast beach. They make squiggly shapes and neat holes in the sand, only to have them wiped out by each incoming tide.

Where this beach is, I don't know, and throughout the film we are never told where we are, other than a visit to Antarctica where we follow the progress of the sleek, purposeful emperor penguins on their epic 200 mile march inland.

Many years ago, there was a BBC TV documentary about this very subject. Many will remember it as one of the finest of all wild life programmes, but strangely it does not detract from the novelty of Deep Blue. Indeed, this is one of the few moments in the film where humour breaks through, despite the penguins enduring temperatures of up to 70 degrees in icy winds, hunched together for warmth as they guard the eggs of their loved ones - dutiful husbands putting humans to shame.

Vast shoals of dolphins show off for the cameras, twisting and turning, diving and romping. In the warm shallow seas around deserted far-flung islands, we undertake an astonishing journey through still living and growing coral reefs. Here the fish have bright and sparkling South Sea island colours. A creature with stag-like horns and Whirling Dervish collar blends miraculously with the ever-moving coral.

Always, there is an uncomfortable feeling that humans are threatening the balance of this majestic canvas. Further north a polar bear swims to the great ice floes for survival, searching with its furry cub for big fish, or seals, trapped in a watery vacuum.

The central, ground-breaking episode of Deep Blue takes us on a journey to the centre of the earth. In the dark depths of our planet lurk some of the strangest and ugliest of creatures. Some produce their own light. Others look like small, see-through plastic containers. A long spinal cord swims by. Less research has been done down here, we are informed, than in outer space. On the flat bottom of the ocean - we are not told which one - lie ravines as deep as Everest is high. From the very, very bottom, up skyscraper chutes, comes hissing steam from the earth's crust.

Wow! Sobering stuff.

Michael Gambon's commentary, whilst admirably sparse, is strangely flat. Sure, we get the big picture, but where's the soul? Although mind-bogglingly dramatic in every way - even the seagulls are portrayed as dive bombers, as they follow the sharks to their hunting grounds - Deep Blue left a lesser impression on me than the gentle and inspired Winged Migration.

It has to be said that I felt a positive pride that the BBC was behind all this. The international cooperation needed to make such a film must be unprecedented. It's hard, I guess, to grab attention when we have been bombarded for years by so many impressive BBC documentaries.

This is a beautiful and brutal blockbuster about the earth's sea creatures and their environment. The never-ending battle for survival poses uncomfortable questions for us all.

Why are we so different? Is not life just a matter of birth, struggle, survival, death and renewal?