Launched in 2004, the 19.1m-long vessel was built by Kelly Archer Boatbuilders in Auckland for United States owners Jim and Jean Foley.
The vessel has been strengthened with a view to operating in Antarctic and Arctic waters and has a fully-laden displacement of 39,000kg.
Onora arrived at the weekend and is expected to sail for Stewart Island later this week, after about a five-day stay.
ORC harbourmaster Steve Rushbrook said that, after a consenting process, the council had established two visitor moorings from the start of summer: one for craft up to 12m long at Deborah Bay, and another for craft up to 20m long at Careys Bay.
The moorings, for short-term visiting vessels, were booked through the harbourmaster’s office, and the first 48 hours in any six-month period was free.
During the two years he had been in his post, Mr Rushbrook said he had received many inquiries from visiting skippers looking for short-term visitor moorings, including as they sought to avoid bad weather or unfavourable tides.
There had since been about eight visits to the swing moorings.
Developing the moorings was "just one of many steps" in establishing the harbourmaster’s department.
This move had already proved "useful and quite successful in providing an asset for people who come to Dunedin", he said.
