THE sight of a father encouraging his small child to play on a weir has prompted a water safety expert to warn others of the danger.

What might seem like harmless fun could soon turn to tragedy, said David Walker, of the Severn Area Rescue Association.

"A weir is the last place you should be. We call them drowning machines," he said.

"There are rocks at the bottom with a drop into white water, where you would lose buoyancy and could quickly get trapped."

Mr Walker is station chairman of the Upton-upon-Severn unit of SARA, which provided safety cover for dragon boat racing on the River Avon at Pershore, last weekend.

There he saw a man encouraging a child of four or five to use the face of a nearby weir as a water slide.

The man said he had done it himself as a child.

Mr Walker said people were largely ignorant of the dangers lurking at the bottom of a weir.

"It looks like a water slide, but it's not Alton Towers," he said.

"If you fell into it, it would be like being in a washing machine. You would lose energy and get pulled down by the swirling water.

"Children don't see the danger at a certain age. It's only when something goes wrong that they appreciate it.

"That's why we give white water safety talks in schools and youth groups."

There are more than 20 weirs in the Worcester area, including those at Holt Fleet, Bevere, Diglis and Upper Lode on the River Severn, with another on the River Teme at Lower Wick.

Rescuing people from weirs is one of the most dangerous types of rescue the Upton SARA unit have to face.

The SARA volunteers have undergone tough training to prepare them for white water rescue and have even got a specially designed deckless rescue boat that can be used on weirs.