Central government are also possibly not keen on the Halsey St base, with Prime Minister Jacinda Ardern a key speaker at a public protest against wharf extensions for port use in 2015.
A spokeswoman for Ardern said the Government is yet to consider these matters, although on Friday, it quoted a senior political source that the Halsey Wharf extension "has to be dead". A second source said the dispersed option on Wynyard, Halsey and Hobson wharves would create a village-type atmosphere and ensure the 2021 regatta is a huge success.
But sources close to Team NZ say: "The Halsey extension is the legacy option. The dispersed options would be there for the Cup and would then disappear. Halsey Wharf would be there for visitors, for super yachts, for triathlon events and all sorts of water-based events. It wouldn't be - and shouldn't be - given over to apartments and the like."
TNZ are also understood to feel strongly that only the Halsey Wharf option allows the number of berths required, not only for challengers but many of the large number of super yachts expected for the next Cup.
The source said: "The dispersed options favoured by the council do not have any room for super yachts."
Peter Busfield, executive director of the NZ Marine Industry Association, was quoted earlier this year as saying 120 super yachts would come to New Zealand for the Cup.
That estimate has since reportedly been upgraded to 140-160 and, with many spending millions on refits and upgrades while here, the industry has estimated a spend of more than $400 million from super yachts.
"That ... far outweighs the cost of the $190 million Halsey wharf option," one source said.
"You also have to take into account the J-class yachts [the class which was sailed in America's Cups 80 years ago, seven yachts ranging up to 76 feet long] want to come and sail here as they did in Bermuda - and they have to be accommodated as well. "
What is also little understood is just how carefully Team NZ have written Italy into considerations in the America's Cup protocol and other binding documentation.
For example, the $5 million granted by the National Government before the election was accepted - but only after it was agreed the money could be paid back if the event was not held in New Zealand. The Cup protocol also had the words "or in Italy" added to the language describing the event as to be held in "the coastal waters around New Zealand".
TNZ's preference to centralise the bases on a 220m extension to Halsey Wharf has been headlined as covering 3 hectares of water space - a description the team feels sounds unfavourable until you realise it is already bounded by Wynyard Wharf and the silos and does not stretch out further into the harbour than existing structures.