Boy, 12, breaks back in cliff jump before riding bike home

A 12-year-old boy has narrowly avoided becoming a paraplegic after he jumped off a cliff a quarry in Victoria.

Vincent Davies will need to spend at least six weeks in a neck brace after he fractured eight vertebrae but incredibly, still managed to ride his bike home from the Moorooduc Quarry.

His mother, Manon Davies, is warning other families to be careful these holidays after her son's accident.

"Just seeing this now, is so confronting and the reality is, he's going to have a tough few weeks ahead of him," she said.

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Vincent, who's supposed to be starting school in less than a fortnight, says it felt like he'd been hit by a car.

"I jumped off first and then I kind of twisted in the air and my back hit the water first," he said.

The 12-year-old jumped off a 20 metre-high cliff at the Moorooduc Quarry on Wednesday afternoon.

Incredibly he managed to ride his bike home but when the pain didn't subside he was taken to hospital.

"I think the reality has only really just hit us, we actually thought we were going to hospital as a precaution that he'd be fine," Ms Davies said.

After hitting the surface, Vincent tried to tread water but he couldn't move his limbs and was winded. If it wasn't for his friend's father who rescued him, the 12-year-old could have drowned.

"I know how lucky I was, and how lucky I am for my friend's dad to drag me out," Vincent said.

Ms Davies said other children need to be warned of the dangers of jumping off cliffs.

"I just hope he never does anything like this again, and more importantly I hope other kids, who are watching this, will think twice," she said.