The ship operator involved in the "embarrassing" bungled delivery of two new Bass Strait ferries has conceded it made a mistake trying to build port infrastructure.
The first of two $900 million Spirit of Tasmania replacement vessels is sitting in Scotland because a required port in Devonport hasn't been built - it likely won't be ready until early 2027.
The saga, dubbed one of the worst infrastructure stuff-ups in Australia's history, has sparked a war of words between ferry operator TT-Line and port company TasPorts.
The two Tasmania-government-owned corporations have been under the microscope during parliamentary hearings this week.
TT-Line interim chairman Damian Bugg said with the benefit of hindsight the company should not have gotten involved in the port build.
"That is an infrastructure build when we are ... a ferry company that is structured and staffed to run efficiently and leanly as a ferry company," he said on Thursday.
"Here we were embarking on a fairly complicated infrastructure task. Mistake number one."
Mr Bugg said TasPorts should have taken steer of the port job and TT-Line should have elevated concerns over delays to cabinet level earlier this year.
"Should I accept responsibility for it? I do on behalf of the company," he said.
"It's an embarrassment to us ... because the people of Tasmania expect better from their appointed representatives."
Leasing options are being investigated for the vessel berthed in Scotland, which arrived there on Tuesday after leaving its construction yard in Finland.
Tasmania's government is paying more than $47,000 a week plus "ancillary services" for a minimum 30-day berth.
An initial broker engaged by TT-Line had presented limited leasing options, but further brokers were being sought, Mr Bugg said.
Transport Minister Eric Abetz defended the Scotland berthing decision, saying it was closer to leasing markets and a trip to house the vessel in Tasmania would have cost "millions".
The second of the new ships is expected to be delivered in 2025.
TasPorts interim chair Amara Doyle on Tuesday said the company completed its portion of the port build on time and didn't contribute to delays.
The leasing ambition has been described as a charade by Opposition Leader Dean Winter who has called for the ferry to be brought to Tasmania.
"The Tasmanian taxpayer is paying nearly $50,000 per week plus other costs ... for an indefinite period of time," he said.
