History is being revealed in the Clutha River below Roxburgh Dam, as ribs of wood and steel break the surface of the water.
Low river levels have made the remains of four gold mining dredges more visible than usual.
The four dredges are Golden Treasure by Millers Flat, Gold Queen between Roxburgh and Millers Flat, Kohinoor by Coal Creek and Jubilee below Roxburgh.
Archaeologist Matthew Sole, of Alexandra, visited the dredges during research for development of the Clutha Gold Trail.
Fragments of Golden Treasure were littered on either side of the river by Millers Flat, "so it is not all in one piece."
Kohinoor was "largely intact" sitting in the middle of the river.
Jubilee broke from its moorings and then sank in the river below Roxburgh, he said.
At the height of the boom in gold dredging in the late 18th century, "we were recognised as the dredging capital of the world".
The early dredges were "like a big spoon" that scooped up river gravel and recovered gold.
First the dredges could only work on river beds "but then they were able to design them so they could eat into the river banks".
Dredges began being powered by paddle wheels, then by coal and steam and later by electricity.
The development of some of the power stations in this region was "basically in order to power dredges", Mr Sole said.
The remains of the first electric dredge was still at Gorge Creek by Lake Roxburgh, he said.
When electric dredges were working particularly hard, straining under the load of digging into rock, particularly around Cromwell, "old-timers" would tell how "all the lights would go dim".
Gold fever remains
Teviot Museum committee member Robin Christie said the Clutha River is a watery grave for at least six gold dredge remains.
Some could be viewed from the Clutha Gold trail, while others were more difficult to spot or required permission from property owners for access.
Kohinoor accidentally sank about 1918 during the dredgemaster’s attempt to break through a high yield "unmodified bottom".
Jubilee can be seen from the gold trail near Ladysmith. It sank at its moorings in 1906.
Gold Queen can be seen below an Ettrick dairy farm.
It caught fire at midnight in 1902 in the middle of the river, only two days after the directors of the company had an on board meeting to evaluate its operation.
Millers Flat Electric was constructed of riveted steel, and worked the East Bank of the Clutha River by Millers Flat bridge before moving to the Tima Burn stream
about 1910.
Permission is needed for access to view.
Golden Treasure is on the West Bank at the start of Island Block near Millers Flat Bridge.
It was listed in the Otago Daily Times for sale as a going concern in 1914, but was dismantled in 1918.
Permission is needed for access to view.
The Pride of the Clutha sank in the river south of Millers Flat, but little remains to be seen, although a tumbler wheel cog was unearthed while ploughing a field nearby.
