It's a heart-in-the-mouth moment that would have most parents running for help.
The massive carnivores loom menacingly over their bite-size pool companions in these remarkable pictures.
But there's more to the scenario than meets the eye, in fact the children are separated from certain death by 10-inch thick plexiglas.
Within touching distance: Children swim incredibly close to two enormous polar bears at a rescue centre with a difference in Ontario, Canada
Both children and bears are actually very safely taking part in an amazing initiative by the owners of Cochrane Polar Bear Habitat, in Ontario, Canada, in a attempt to promote awareness about the amazing animals.
The sanctuary takes in only bears rescued from the wild and through letting visitors get so close they hope to foster understanding and reduce hunting in the wild.
Former director at the centre and keen photographer Gerry Robichaud took the amazing photographs of the moment bear meets man in the safety of the tank.
They're behind you: A child keeps his head above water as the two bears swim towards him - but everything is not as it seems
He said: 'You do get some very surprised reactions from visitors when they first see the bears and the children in the pool.
'When you're in the water and up by the glass next to these animals it barely seems like there is anything protecting you, when in fact there's a 10-inch think barrier.
'We get various reactions from the children, some of them can't wait to get in the pool and others really don't want to. It's the adults you have to watch out for, some of them jump in still with all their clothes on.
'The two bears in the pictures are actually females, Aurora and Nikita, both who we took in as rescue animals.
Centre of attention: The children gather round the bear - but a 10-inch wall of plexiglass keeps them safe from the cute but deadly dangerous bears
'They came to us a cubs after a tribe told us about them because their mother had been shot by a hunter near Winisk, near the Hudson Bay in the far north.'
Gerry, 59, said the aim was to give the bears as much stimulation as possible in their 100m by 200m enclosure.
He said: 'I have been in the water myself when the public have not been here and actually realised one of the bears was stalking me, she was hiding and keeping very low in the water. It was quite an odd feeling.
'I have lived in the far north with the people up there myself and documented their lives, it's a different world up there.'
Read more: Children swim inches from monster polar bears | Mail Online