Sirena's involvement with Team NZ extends the close working relationship between the Kiwi and Italian syndicates.
The Kiwis helped Luna Rossa with their late entry at the last America's Cup, handing over the designs from the first of the two New Zealand foiling catamarans.
Since Luna Rossa's withdrawal from the 35th America's Cup in Bermuda, they have thrown their support behind Team NZ, lending them a testing boat and sharing data gleaned from their trials.
The acquisition of the boat, with an AC45 from the now-defunct Australian challenger, ensured Team NZ matched the resources of their well-funded rivals, Oracle Team USA and Artemis, giving them the ability to conduct proper testing, and also conduct crew selection trials and in-house racing.
"We've got a very good connection with Luna Rossa from the past, and with their assistance to us now, which has been really huge for us. They've plugged holes we had or areas where we thought we could do better and it's working out really, really well," Shoebridge said.
A lot of this is just about getting good people and then we figure it out.
Sirena's arrival in Auckland will boost Team New Zealand's numbers to 52 ahead of what will be a busy summer of testing. Shoebridge said although many elements of the America's Cup class will feature one-design components, there are still development gains to be made, but efforts will be concentrated on two areas: dagger foils and control systems.
"The test boats are really important," he said. "A lot of what you learn in the test boat will be directly transferred over to the race boat. The race boat will really be the summary of all the work that you've done in the years previous."
The testing programme will also double as an opportunity to develop the sailing team, with several youngsters chasing a place on the race boat for the 2017 regatta.
Team New Zealand skipper and sailing director Glenn Ashby has recruited a group of young, athletic sailors, as well as Olympic rowing champion Joseph Sullivan.
"The [America's Cup World Series] regattas are great to be out there racing, but the race boat will be a slightly different animal," Shoebridge said. "It will require different expertise on board. It will be different crew positions. We need to make sure we've got the right people in the right places."