Since Titanic, director James Cameron has spent most of his time on the ocean floor, surfacing only to release documentaries and take on fresh sandwiches. His latest educational effort, Aliens Of The Deep, asks whether the strange creatures that thrive around volcanic vents beneath the sea could help us to discover life elsewhere in the solar system. Like many IMAX films, it's worth a look for the razzle-dazzle photography, but don't expect much in the way of serious science.

But first let's deal with that title, because frankly it's a bit misleading. James Cameron's Attack Of The Prawns might have been better, since you spend a hefty portion of the movie flinching back from swarms of grumpy shrimp. Cameron is your guide to this crustacean festival, and he's a delightfully hard-bitten host, drawling manly cliches - "Here's the deal: I love this stuff" - in his best Ed Harris voice. If anything, he's slightly geekier in 3D: his beaky nose springs right out from the screen to snuffle at your popcorn.

"FEELS LIKE SOMEONE WAVING A FISH IN YOUR FACE"

Cameron works hard to instill a sense of awe, but despite hushed voice-overs and orchestral harmonies, the film feels basically like someone waving a fish in your face. Still, it would be mean to mock the technical achievement here; the difficulties of shooting IMAX footage on the ocean bed are mind-boggling. Cameron has found some fine fish too from satin scarves with gills to giant squid, and when the underwater stuff gets dull, there are some breathtakingly implausible CGI sequences to enjoy.

Aliens Of The Deep is released at the bfi London Imax Cinema on 11th February 2005.