I am not sure a campaign aimed at only this is the answer. We have to remember that teenagers are 'hard wired' to take risks, research shows it is literally in their biology. Risks are varied and can be positive - a sport, playing an instrument in front of folk, a new friend group, behaving or dressing differently etc. But it can also be negative - often teens reach for drink, drugs, sex... The issues here fore me are so many children grow up without learning the skills and emotions of risk management, and so many children grow up without the appropriate feedback loop around risk taking that enables them to apply it elsewhere. We have to enable children, from a very young age, to experience and manage risks and fear. We cannot wait for that to happen when it is teenage years, when the risks they face increase in consequence exponentially - things like being dared to jump off things, being handed a drink at a party, being offered a lift in a car with a new driver...
But please not another very specific campaign or warning that deep water is always dangerous. I have spent my whole life swimming, sailing, canoeing, kayaking, gorge walking and more, both for my own fun and teaching children and young people that outdoor sports are fabulous, that nature is wonderful and healing place, and that adventure and risk is good for us all.
I also think that if there is any campaign it is about more swimming lessons for all children and more access to the natural world.