FIREFIGHTERS shared a photo of an empty packet for a pair of armbands as they issued a fresh warning about the dangers of swimming in open water.
South Yorkshire Fire & Rescue said it indicated non-swimmers had been taking a dip in the canal at Holmes Lock in Rotherham.
They said they had received reports of up to 20 people swimming at the spot.
Several people have drowned after getting into the difficulties in lakes and waterways in recent weeks, most recently in Crookes Valley Park in Sheffield.
Fire officials said they did not want to discourage swimming in open water by organised groups following safety procedures, but the public needed to be aware of the risk of shock, disease and becoming caught by submerged vegetation or items.
Sharing a photo of the packet for a set of armbands on social media, the fire service said: “Obviously the thought of anyone using a canal for swimming is bad enough, but the thought of non-swimmers who need armbands to stay afloat is a terrifying one.
“Please respect the water and keep your children out of places like this.”
A water safety awareness event is being held at Rother Valley Country Park from 2pm to 5pm on Sunday.