Water company United Utilities is urging young people in the North West not to let their friends swim in reservoirs this summer.
Two men have already drowned this year in unrelated incidents in Bolton and Gorton.
The warning campaign has the backing of Beckie Ramsay.
Her son Dylan was just 13 when he got into difficulty swimming at Hill Top Quarry in Whittle-le-Woods, near Chorley, in July 2011.
Dylan's mum has spent the past 7 years warning of the dangers of swimming in open waters. She's a launched a petition calling for water safety and the dangers of 'Cold Water Shock' to be taught in school.See the petition here
Youngsters (aged 13-19) in the region are most likely to get into a reservoir if the weather is good according to new research from United Utilities – despite 70% saying that they believe reservoirs are dangerous
Data shows that peer pressure is one of the main reasons why teens swim in a reservoir
One in ten have ‘tombstoned’ (jumping from height into water)
This is a powerful video warning youngsters of the dangers of open water and reservoir swimming which is costing lives.