In a poll carried out by the BBC on the 60th anniversary of the COI in 2006, Lonely Water was chosen as the UK's fourth-favourite PIF of all time and the highest ranked one-off production.

[2] Lonely Water was directed by Jeff Grant and written and produced by Christine Hermon for Illustra Films, having been commissioned by the COI as a result of official concern over the high number of child fatalities in drowning accidents in the UK.

Other PIFs of the early 1970s to tackle the subject of water safety included an instalment of the Charley Says series and Learn to Swim featuring Rolf Harris, which were targeted at younger children and parents respectively.

"I am the spirit of dark and lonely water: ready to trap the unwary, the showoff, the fool..." intones the voiceover, "...and this is the kind of place you'd expect to find me.

She picks up the robes, but throws them into the water in disgust (the girl's line, which baffled many viewers[citation needed], is "Urgh...'orrible fing!"

Gone was the gentle cajoling of Rolf Harris, who had recently appeared in a public information film aimed at persuading children to learn to swim.

"[4] It was posited that the COI were being "irresponsible" and "foolhardy" with such a frightening script, though Grant praised the creative latitude it gave him as director, "something you more often than not had to fight for".

Initial difficulties with the filming included getting the smoke to drift in the right direction, constructing a wooden platform for the spirit to stand on, and the noise of aircraft flying overhead due to the shooting location being close to Heathrow Airport.