The last of up to 20 mothballed oil and gas rigs parked up in the Cromarty Firth is to leave for a new drilling contract.
The firth has long been an anchorage for rigs
High oil prices and a world shortage of platforms have led to all of them being returned to working order.
The last rig, Wildcat, has undergone a major refit after it was bought by Indian company Essar for £140m.
It will take 90 days to tow the platform from the Highland firth to the east coast of India.
Captain Ken Gray, of Cromarty Firth Port Authority, said the firth was a good barometer of the state of the oil industry.
He said: "When you look at it now there are no rigs in the firth basically because everybody is out drilling and finding more exploration.
"It's probably a good indication how the trends are.
"As long as we have got North Sea crude or crude oil in the world and there is this large demand and high price then all the rigs will be out there working."
A spokesman for Essar said it had made sense to refurbish the Wildcat in Cromarty because of the quality of the local workforce and contractors.
Roy MacGregor, of Global Resources which carried out the work, said there was demand for secondhand rigs.
He said: "There is a worldwide shortage of rigs and if you want to buy a rig straight off a shipyard you will have to wait four or five years."
The sight of rigs stacked up in the firth has had a surprising impact on Scottish literature and tourism.
Novelist Christopher Brookmyre's book One Fine Day in the Middle of the Night features an ill-fated school reunion on an oil rig in the process of being converted into a luxury hotel off the Highland coast.
Meanwhile, Harrods owner Mohamed Al Fayed had a plan to transform an oil platform in the Cromarty Firth into a country house-style hotel.