Complete with smoke coming out of its nostrils and dragon sound effects, some of the youngest party-goers were initially too scared to get close, but quickly warmed to the lovable giant as it whirred around the river.
Owen, a duty manager at the Olympic Pools Complex for about 20 years, made the dragon as an after-work project.
He spent several hours making a model to figure out how the jaw and wings would move, then constructed the final project by draping tarpaulins over a metal armature and chicken wire frame he attached to his sailing dinghy. He carved the dragon's head out of polystyrene.
The dragon gets its speed from an outboard motor and can spurt water from its mouth, thanks to a well-hidden fire extinguisher.
Owen enjoys making people happy building projects like this and with six young grandchildren to entertain, he's always mulling over the possibilities.
For his grandson's previous birthday, he converted the dinghy into a pirate ship.
He also enjoys sharing his efforts with the wider community.
Among his previous creations are the elephant and dolphin in the toddler pool at the Olympic Pools. Those have proved so popular over the years they are being kept as part of the redevelopment of the pools.
But the dragon is unlikely to be seen again.
Owen says the long weekend was its final outing and he has retired it to its cave.
He's going to dismantle it so he can get his sailing dinghy back and is pondering another artistic creation for next summer.