The last voyage of the world's oldest surviving clipper ship is to be revealed in a new book.

The City of Adelaide transported thousands of settlers from Europe to Australia in the 19th century before ending up in Irvine, North Ayrshire.

Scottish author Rita Bradd was granted exclusive access to accompany the 150-year-old ship on its final 14,000-mile journey around the globe.

She was given permission to join the crew of the cargo ship MV Palanpur, which carried the clipper from Rotterdam in the Netherlands to its final resting place in Port Adelaide in South Australia, where it arrived safely earlier this year.

The tall-ships enthusiast kept a diary in tandem with that of a young woman who made the maiden voyage in 1864, charting the ups and downs of the trip - from spending Christmas Day on the equator to surviving a cyclone.

The journey marked the culmination of the latest chapter in the 450-tonne clipper's eventful life.

Researchers estimate that a quarter of a million South Australians can trace their origins back to passengers who travelled on the City of Adelaide.

Its sailing days ended in 1893 but in later years it was used as a hospital ship, renamed Carrick as a training boat and a clubhouse, and was raised and kept on a slipway at Scottish Maritime Museum in Irvine after sinking in the River Clyde in 1991.

Charitable organisation Clipper Ship City of Adelaide led a successful campaign to save and relocate the boat to become part of a new maritime heritage park in South Australia.

The group beat a rival bid from campaigners in Sunderland where the ship was built.

Mrs Bradd, whose book will include the stories of many of those who have been involved with the clipper over the years, recalled the "huge sadness" of the day the boat left Scotland bound for Greenwich in south east London and on to Rotterdam.

She said: "The ship is a people's ship. She's just got such an amazing presence.

"She's done so many interesting things in her life and she's lived through all these hardships. She just captivates people's imaginations.

"It's an incredible story, not just my part in it, but the whole ship and the people who have been involved with her and the passion that bubbles out from everybody."

The 70-day voyage took her from Rotterdam to Norfolk in Virginia, US, and on to Port Hedland, Western Australia, via the Cape of Good Hope, following the historic route the ship would have taken in its heyday.

Recalling the final and most precarious leg of the journey, Mrs Bradd said: "We hit the tail end of a cyclone and it was really wild.

"I quite like a bit of a thrill but that was just a little bit scary and I did think 'Am I ever going to see my family again?'. I really did.

"I was always imagining what it would have been like being inside the ship in storm-force winds, it must have been awful.

"When I saw the land, I was so relieved. I was overcome with joy at the safe arrival of the ship and for that wonderful engineering experience to have been such a success.

"It's a fantastic thing that she has been saved and she looks great out there."

Mrs Bradd has pledged to give a percentage of what she makes from the book towards the City of Adelaide in the future.

"She's given me this wonderful experience and you can't not give something back," she said.