A 10 year-old girl has become the first person in the UK to be saved by a new computer monitoring system installed in a swimming pool.

The girl lost consciousness in the deep end of the Bangor Swimming Pool in Wales and sank 12ft 6ins to the bottom.

The computer software, which uses eight underwater cameras to track swimmers, alerted a lifeguard within 10 seconds and the girl was rescued.

Bangor is one of the deepest swimming pools in the country and the Poseidon system was installed in May 2003 by French company VisionIQ.

Poseidon matches the behaviour of swimmers in the water to a database of thousands of warning signs of a swimmer in trouble and sends a text message to the nearest lifeguard's waterproof pager. 

"We realised after seeing Poseidon that CCTV technology is designed to revisit an incident that you have recorded, not to alert you to an incident," said Brian Evans, a leisure officer at Gwynedd County Council.

"The Poseidon system warns lifeguards in real time that something suspicious is happening, and notifies them of the exact location of the incident. There is no need for them to be watching screens."

The incident happened last Wednesday but images of the rescue have only just been released after the girl made a full recovery in hospital.

Five pools in the UK have the Poseidon system installed: Oxford University Sports Centre, The Pavilions in the Park in Horsham, Canons Leisure Centre in Mitcham and Leaplish Waterside Park near Hexham.