"There is a world of difference between reclamation permanently, and dolphins for 15 years or until we find a permanent location. It is like chalk and cheese."
Goff said the cruise ship industry was "huge" for the city.
"[Tourism] is probably our biggest industry, and the cruise ship industry provides about 3000 jobs and is worth $200 million."
The wharf could currently provide for cruise ships up to 294 metres but the dolphins would allow for ships of up to 362 metres.
As the ships got bigger they could not berth here, meaning passengers needed to be ferried in from further out in the harbour, Goff said.
"By the time they finish unloading everyone they have got to turn around and leave. As more and more ships come it comes at a cost if we cannot properly cater for them, meaning jobs and incomes."
Goff said he was "pleased" the commissioners had arrived at the conclusion the impact on the environment would be able be "avoided, remedied or mitigated", and the economic and social benefits outweighed any downsides.
The council was looking to develop a permanent site for cruise ships on Captain Cook Wharf, when it became available from the Ports of Auckland, or Bledisloe Wharf, if that became available, Goff said.
Panuku Development Auckland lodged the resource consent application in July last year, which was followed by public submissions and five days of hearings.
Numerous community and urban design groups have been fighting to stop the dolphin proposal, opposing further expansion of the harbour for port use.
Stop Stealing Our Harbour spokesman Michael Goldwater said allowing consent to be given was a disappointing outcome.
"We should be using existing infrastructure to berth these boats," he told Newstalk ZB.
"This resource consent outcome is a failure of leadership by Mayor Goff and Auckland Council, who have valued corporate welfare for the cruise industry over the long-term wellbeing of our harbour.
Goldwater highlighted the potential environmental impact the extension could have on the harbour as a major concern.
Panuku Development chief operating officer David Rankin said the decision was being welcomed by the organisation.
The decision will enable to necessary infrastructure for the cruise industry to ensure continued growth to the sector, he said.
"The decision has thrown a lifeline to the cruise industry, which is facing increasing pressure from international ports to compete as larger ships continue to enter the market," he said.
New Zealand Cruise Association chief executive Kevin O'Sullivan also agreed the decision was an important win for the local industry.
"It will ensure that Auckland will continue to be an important and integral part of regional cruise tourism," he said.
"The provision of infrastructure for these larger cruise ships in Auckland will integrate well into the considerable development of infrastructure of large ships which has been carried out in other New Zealand ports."
Following the decision from the commissioners, an appeal period is now open until May 15 for those who made submissions on the application.
