The City of Adelaide, built in 1864 to take migrants from Europe to Australia, is being readied to voyage south for the first time in more than 125 years.
It has been kept on a slipway at the Scottish Maritime Museum in Irvine since it was salvaged in 1992 after sinking in the Clyde the previous year.
The museum could not afford to refurbish the ship and had applied to demolish it to save parts of the vessel.
The new owner, Clipper Ship City of Adelaide, launched a successful campaign to save and relocate the vessel, which will be part of a new maritime heritage park.
The group beat a rival bid from campaigners in Sunderland, where the ship was built.
The clipper had been regarded as unrecoverable due to the silted river and protected wetland areas around its berth in Irvine, but engineers in Australia created a steel cradle to allow the ship to be rolled across a temporary bridge over the river surface and on to a low-draft barge.
The City of Adelaide is due to leave Irvine within days, depending on weather conditions, to be taken by barge to Greenwich in south east London.
There it will be moored beside its sister ship, the Cutty Sark, before being lifted into the hold of a cargo ship to make the journey to Australia.
Clipper Ship City of Adelaide director Peter Christopher said: "I can almost picture the spectacle as the clipper is transported up the River Thames to Greenwich, bringing together the two last original 19th century clipper ships.
"This has been a team project from the start, and the level of commitment and passion has been quite extraordinary."
The Carrick was built in Sunderland in 1864 but has been in Scotland since the 1880s and around the Clyde since 1924 when she was converted into a training ship and renamed HMS Carrick, and subsequently into a clubhouse in Glasgow.
In 1991 the ship sank at Princes Dock in Glasgow, and lay on the bottom of the river for a year before being raised and returned to Irvine.