'Everyone thinks they're bullet-proof': Quadriplegic man's warning after fracturing his neck in pool dive

A young quadriplegic has used the first anniversary of his life-changing pool accident to issue a stark warning.

Champion water polo player Nick Dempsey fractured his neck when he jumped into a backyard pool on his 21st birthday.

He'd dreamed of going to the Olympics and had already represented Australia in the junior water polo team.

But that dream was shattered when he misjudged his dive, hitting the bottom of the pool and dislocating his neck.

The apprentice plumber spent eight months at the Austin Hospital in Melbourne and is now a quadriplegic.

"Everyone thinks they're bullet-proof and it won't happen to them," Dempsey said.

"I was a water polo player, spent all my time diving in pools, and still managed to misjudge when I hit the bottom, so it can happen to anyone."

Three people are still in intensive care after diving accidents last month.

Authorities say young people are not getting the message that if you dive into water that you could stand in, you can break your neck.

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"This is entirely preventable if people check their environment, the depth of water, obstacles," Austin Health's Dr Andrew Dunn said.

"Look after your mates and make sure none of you dive into water where you don't know the depth."

Nick Dempsey says he wants to use his story to remind others how a split-second decision can have-life-changing consequences.

"Don't wrap yourself in cotton wool, just be smart before you jump in," he said.