Directed by Chris Kentis, starring Blanchard Ryan and Daniel Travis.

Praised by numerous magazines and benefiting from one of the better trailers of recent years, the tiny-budgeted 'Open Water' has done great business in the US and looks set to do a 'Blair Witch' in Europe also. Made by the husband and wife team of Chris Kentis and Amanda Lau, it recalls the spirit of the cheap and cheerless shockers of the 1970s and 1980s and will probably see another revival of the whole scares-on-a-shoestring genre.

Exhausted by their successful careers and with their relationship strained, Susan and Daniel (Ryan and Travis) decide to take a break in the Caribbean. Switching off and doing nothing, however, isn't easy and on their first full day the certified scuba divers head off for an underwater tour on a charter boat. Packed with tourists, the boat arrives at the dive spot and gives the passengers 40 minutes in the area to explore. But problems with simple mathematics and a mix-up with who is and isn't in the water mean that when Daniel and Susan surface the boat is gone.

There's no doubt that 'Open Water' is a great idea for a film and taps into audiences' fascination with sharks that began with 'Jaws' nearly 30 years ago. But there's no Chief Brody, Hooper or Quint here and, even at 80 minutes, it's thin on terror. While actors Ryan and Travis did suffer for their art (120 hours in the water, real sharks as co-stars, chainmail underneath their wetsuits in case they were attacked), their sacrifice isn't rewarded with a decent script - viewers brains go wrinkly if they hear lines like 'I'm cold' and 'There's something against my leg' too much. And with a 20-minute build-up before the tanks go on, and cutaways later of others having fun back on the island, 'Open Water' is a short film that has been stretched to the limit.

Not likely to help scuba diving become the world's most popular pastime, but only scary if you're already frightened of your own shadow in a cinema.

Harry Guerin