But with the cost of providing all-tide access to the pontoon estimated to be $70,000, and an upper estimate of up to $90,000, the group has plenty of fundraising to do.
The call, from the recently formed Careys Bay Access Committee, will go before the Dunedin City Council's annual plan hearings, which begin today.
The idea has attracted more than 70 supporting submissions from organisations, including the New Zealand Marine Studies Centre, the Otago Peninsula Community Board, tourism operators and commercial fishers.
The main submission, from committee secretary and Careys Bay Hotel publican Jo Kidston, said the Otago harbour was underutilised.
"With a view to improving this situation, we believe the existing infrastructure should be improved to a usable level."
To add to Dunedin's status as a centre of nature tourism, the extended pontoon would allow water-based transport from Careys Bay to Portobello or Wellers Rock without a long drive around the harbour, and allow cyclists to complete a round trip from the port to Portobello, then across the water to Careys Bay.
As well, cruise ship passengers could be taken to Quarantine Island or the University of Otago's marine studies centre at Portobello.
The main aspect of the proposal was strengthening and extending the pontoon, and dredging in the area.
The total cost was expected to be between $46,000 and $90,000, but a supplied estimate has suggested about $70,000.
Apart from asking the council, the committee would request funding from Port Otago, through a fee from commercial users and through grants from community organisations.
Ms Kidston said yesterday planning for the idea was still at an early stage, and she was unsure how much would be required from the council.
Before the committee got some sort of backing from the council, it was difficult to do more specific planning.
The situation was the same for the cost of maintaining an upgraded pontoon, though Ms Kidston said the plan to require commercial operators to pay a fee would provide an income.
Monarch Wildlife Cruises owner John Milburn, who is also on the committee, said the idea had been put to the city council and the Otago Regional Council in 2004, but had not gained acceptance at that time.
"We determined the best way to progress it was to get it in the annual plan process."
A wide range of people would benefit from the upgrade, Mr Milburn said.
The committee's submission has been listed for tomorrow morning.
Pontoon upgrade
Pontoon extension: $10,000 to $50,000.
New piles: $15,000.
Alterations to pontoon and gangway: $5000.
Dredging: $16,000-$20,000.
