The Duke of Sussex turned his focus from the Invictus Games for wounded war veterans to the environment on the seventh day of his royal tour of Australia.

His first engagement was to dedicate the K'gari/Fraser forest to the Queen's Commonwealth Canopy, a network of forest conservation initiatives, which involves most countries of the Commonwealth.

He said the project was committed to raising awareness of the value of indigenous forest and to saving them for future generations.

"Put simply, without trees and forests we don't survive. It is a symbiotic relationship and one that so many people still fail to realise," he said in his dedication speech.

Harry praised the island, which he on Monday explored and learned about from the local Butchulla and others.

"As you all know too well, K'gari means paradise and that is certainly what we've experienced today," he said.

"It is up to us now to protect this paradise together, not just because it looks beautiful, but because it is a essential part of our existence and will continue to be for our children and their children's children."

The 206,970 acres of pristine rainforests is the second Australian forest to be added to the Queen's Commonwealth Canopy project.

In a space between towering satinay trees in Pile Valley, the prince received a blessing from the Butchulla who performed their smoking ceremony, welcoming him to K'gari.

After a special walk to the island's Big Tree, a satinay 1000 years old that survived Fraser's logging past, he emerged into a clearing to a rapturous welcome.

Aunty Mally Clarke drew laughter from the crowd and the prince when she called out "he's even better looking in person".

"I'll take that as a compliment," Harry said from behind the microphone set up in the forest clearing.

Harry shook hands with each dancer before an impromptu meet and greet among those gathered in the forest before leaving to see the crystal clear fresh waters of the island's iconic Lake McKenzie and a trip along the beach.

There he took off his shoes and walked barefoot in the shallows and spent quite some time talking locals who showed him around the white beach on the world's largest sand island.

It was a perfect, sunny Queensland day for the royals to visit the world's largest sand island.

The Duke had earlier travelled from the Queensland mainland to Fraser Island on the bumpy barge just like almost any other tourist, while a pregnant Meghan took a more sedate journey on a cruiser.

Harry was to have been accompanied by Meghan for the day's engagements, but she stayed behind at one of the island's resorts to rest.

She joined him later in the day, dressed in a white sun dress with black stripes, for a walk on Kingfisher Bay Jetty.

Prince Harry also met Premier Annastacia Palaszczuk who gave the couple a hand-made teddy bear from Tambo, in the heart of Queensland's sheep country, for their first baby expected in the northern spring.

Hervey Bay paramedics Graeme Cooper and Danielle Kellam will meet attend an official reception.

They'll be recognised for their act kindness after a photo of them granting a dying woman's wish to see the ocean one last time went viral and captured hearts around the world.

Australian Associated Press