Floods had washed away the stinger warning signs on the bank of the Calliope River when 10-year-old Rachael Shardlow waded into the shallows in December 2010.

She didn't want to be swimming in the estuary about 15km from Gladstone, Queensland, and had even thrown a tantrum before leaving the house with her parents and older brother Sam that day.

Perhaps it was an omen because minutes after entering the water, Rachael was stung by a deadly box jellyfish.

READ MORE: Fiji resort linked to suspected drink poisonings revealed

Found in warm waters from Western Australia to Queensland between October and May, box jellyfish are the most venomous marine creature on the planet and can kill a human in minutes.

Despite this, researchers still know next to nothing about the deadly creatures that almost claimed Rachael's life 14 years ago.

"I do remember being nervous about going in the water. I asked mum, 'is there anything in here that can hurt me?'" Rachael, now 24, told 9news.com.au.

Have you got a story? Contact reporter Maddison Leach at Google Play.