A quiet afternoon fishing trip has turned into a rescue mission to help a large turtle caught on mudflats in North Queensland.

Chris Woods and his son, Finlay, had been at their usual fishing spot at Sunset Bay in Mackay, when they noticed the large female green turtle stranded in the mangroves.

The pair tried to build a barrier to keep water around the 100-kilogram reptile as the tide went out.

"They tried to refloat the turtle, but it failed due to her size," said Mr Woods' wife Kym.

A group of bystanders help lift the green turtle which weighed nearly 100 kilograms. ( Supplied: Kim Woods )

"Once they got close to her they saw the turtle was injured and missing part of her jaw, so they called for help."

Rescue mission

The group of volunteers had to haul the turtle on a blanket to the awaiting transport. ( Supplied: Kym Woods )

A group of people was quickly called together to help move the turtle from the mudflats.

David Bowen from Mackay and District Turtlewatch praised the efforts of Chris and his son.

"The young lad was pouring water over her to keep her wet and calm, it was lovely," Mr Bowen said.

A group of Mackay locals get together to lift the injured green turtle and carry it to a waiting ute. ( Supplied: Kym Woods )

"She was just sitting there quietly and not distressed … she seemed to be in very good condition."

Mr Bowen then helped coordinate the task of carrying the turtle more than 100 metres to his ute.

"We needed about four rest breaks along the way," he laughed.

"They are quite compact for their weight, so it can be difficult to carry."

The turtle was then loaded onto Mr Bowen's ute and driven to Calen, about 50 kilometres away, where they were met by a volunteer from a rehabilitation centre in the Whitsundays.

Members of the group were trained in marine strandings and helped ensure a safe trip for Demi. ( Supplied: Kym Woods )

'One of the healthiest we've seen'

Libby Edge from Ecobarge Clean Seas, which runs the turtle centre, said it was a miracle that the turtle was in such good condition.

"The injury to her face is horrific, but it's something she's had for at least 10 years," she said.

"I'd say she's about 60 years old and she's done well to survive, she deserves a medal!"

The injured green turtle on towel ready to be lifted to safety — its face has an obvious healed facial injury. ( Supplied: Kym Woods )

Ms Edge said it is likely the injury was caused by a boat.

"I'd say, as she's come up for air she's been hit by the prop on a boat — it doesn't look like a shark attack," she said.

"It's the most interesting case I've seen and it's quite striking that she's survived for so long."

Hoping to head home

The turtle, which has been named Demi, will spend the next five days at the rehabilitation centre in the Whitsundays.

Demi the turtle, resting up in an enclosure at Ecobarge Clean Seas in the Whitsundays. ( Supplied: Fiona Broadbent )

That will give carers a chance to see how she feeds and eats and if there are any other health concerns.

"She's lucky because her diet is mainly seagrass, so she doesn't have to chase her food," said Libby Edge from Ecobarge Clean Seas.

"Even though her injury is horrific, we are hoping to get her back out into the ocean."

Finlay Woods holding up the flyers he was given by Turtlewatch and photos of the rescue operation. ( Supplied: Kim Woods )

"She's survived well in the wild, so there's no need to keep her in care and we need her back in the waters.

"She's touched all our hearts in the space of a night."

An amazing life lesson

Kym Woods said it was a great experience for her young children to be involved with.

Finlay's older sisters, Chloe and Gracie also played a part in helping to keep the turtle wet and cool.

"They all watched in awe during the rescue and being able to be so close to such a magnificent creature," Ms Woods said.

"They've all gone to school today armed with pictures and brochures to tell their classmates about an experience they'll never forget."