THERE'S nothing as inviting as a stretch of cool blue water on a sweltering hot summer's day.

But there's a place and a time for tearing off our clothes and plunging beneath the surface - and the River Severn during the Upton Jazz Festival isn't it.

At least one young reveller who decided to take a dip at last weekend's event thought he was at the seaside or in a swimming pool.

The difference is that at the beach or in a pool you don't risk being cut to ribbons by the churning propellers of pleasure boats.

The lad in question was obviously oblivious to the dangers of a busy waterway, because when he clambered out of the water after attempting to swim underneath a 12-tonne vessel, he was described as 'grinning like a Cheshire cat'.

The river rescue team was scrambled to deal with the incident and soon wiped the smile off his face.

But it shouldn't have taken a telling-off to make him see how stupid his actions were.

There's something about sunshine and water that makes people behave like idiots.

And it seems even boat owners aren't immune - several were criticised for reckless or thoughtless manoeuvres last weekend.

We don't want to see a repeat of the incident that marred the 2003 Stourport Land and River Carnival, when an overloaded boat capsized and a woman drowned.

The Upton Jazz Festival is a marvellous event that is enjoyed by thousands of people every year.

It's not worth dying for.