THE NSW Government's maritime heritage team are working closely with the Tweed Valley Museum at Murwillumbah and Cudgen "wreckspotter" John Gilbert to record and document sites in the Tweed River.
In the last 12 months, retired commercial diver Mr Gilbert has found four cane barges at Condong and two wrecks near the mouth of the Tweed River, which the heritage team had no knowledge of.
Mr Gilbert has been a "wreckspotter" in the Tweed area, both in the river and offshore, for about 18 years.
He's interesting in finding out about a wreck's purpose and history.
Once found, a wreck or relic is mapped and recorded by the heritage team, led by Dr Brad Duncan.
"I guess my favourite at the moment is the one near the north wall of the Tweed River entrance," Mr Gilbert said.
"Once I had a dive on it, I was very interested to try and identify it, as originally I thought it was the tug Terranora, but the remaining engine and boiler appear too big to be that vessel.
"My favourite wreck offshore is the Alberta which was wrecked in 1890 on the outer reefs off Kingscliff. It was about 2214 tons."
Maritime archaeologist Dr Duncan works closely with Mr Gilbert and has recently completed his second visit to the Tweed.
"The trip was very productive.
"We investigated reports of two new wreck sites and historic wharf remains at Tweed Heads and Murwillumbah," he said.
"Closer inspection of the wreck/wharf site at Murwillumbah also revealed the partial remains of another timber vessel, along with two small boilers used to produce steam."
Dr Duncan said seven wrecks had been reported and inspected so far in the Tweed River.
Sugar cane barge graveyards have been discovered in the Clarence and Tweed rivers - at Harwood Island and Condong.
"Although they were remarkably plain vessels, these barges were used to transport the sugar cane and other produce up and down the rivers," Dr Duncan said.
"As such, they were essential components of the industrial and social landscapes of these rivers, and their wrecks and other associated infrastructure - such as wharves and mooring pylons - represent symbols of a bygone age where rivers were the highways to the interior.
"Another favourite is the wreck of the tug Champion II at Ukerebagh Island, Tweed River.
"Although it is located in shallow water, the local currents have scoured the sand away from the bow section, creating an impressive five-metre hole around it which is easily snorkelled by local divers."
Historic shipwrecks and maritime relics in rivers are protected under the NSW Heritage Act 1977.
Tweed Regional Museum director Judy Kean said her staff were working with the Office of Environment and Heritage to register all the wreck relics in the museum collection, many of which were currently on display until August as part of the WRECKED! exhibition.
Ms Kean said rivers such as the Tweed contained important historic wrecks and remains.
"As the main transport routes for passenger and commercial traffic over many years, they carried a busy stream of traffic and wharfs dotted their banks," she said.
Dr Duncan said about 2500 historic maritime sites had been recorded in NSW.