Deep Blue

Herald rating: * * * *

A feature-length compilation of some of the highlights from the David Attenborough BBC series Blue Planet, this eye-popping, big-screen documentary focuses on the oceans, as its title suggests.

Predictably enough, the footage is extraordinary. We watch from shore as orcas risk beaching themselves to snatch unwary seal pups, and from underwater as dolphins herd schools of fish into succulent columns of prey.

Much of the film's first half depicts the ocean as an endless bloodbath of predator, prey and scavenger, but when the film moves into the ocean's depths it takes on another tone entirely, discovering animals that might have been dreamed up at Weta Digital.

These glowing, fizzing, sparking creatures, which live life at a pressure of 500 atmospheres, look more like spacecraft than marine life and make the film a stunning, visual adventure.

The fruity narration, intoned by Michael Gambon, is less successful. The purple prose cloys ("the endless expanses of the watery desert"), and long sequences are completely without narration so we don't even know what we're looking at.

The sound effects, added in post-production, are irritating and banal, too. We can see that a bird is swift without the aural cue of a "whoosh".

And the score is mostly lush and sometimes silly.

It is all very well to have a beach full of sand crabs dancing to a samba beat, but it would have been good to know why they were making little balls of sand.

DIRECTORS: Alastair Fothergill, Andy Byatt, Martha Holmes
RUNNING TIME: 90 minutes
RATING: Exempt
SCREENING: Rialto, Bridgeway