The steel hull of the yacht survived the blaze and the engine room appeared undamaged, said Eaglen, who was allowed to inspect the yacht for the first time yesterday.
The owner of the superyacht, Hong Kong-based businessman Richard Beattie, is in meetings this week to decide if the vessel is salvageable.
The yacht was being built for Aquos Yachts, of which Beattie is chairman.
Beattie said he was concerned by the "potentially devastating consequences" for the Kiwi builders behind the "extraordinary project".
"Our hearts go out to the shipyard workers and to the Porter family [who own McMullen and Wing]," Beattie said.
Star Fish, the successor to Aquos Yachts' $58 million craft Big Fish, was nearing completion and was set to be launched by June next year.
"While the fire ... is a terrible setback for both Aquos Yachts and the shipyard, we remain committed to our core mission of designing and building the finest luxury expedition yachts in the world for discerning yacht owners wishing to explore the world in the highest levels of comfort and security," Beattie said.
Eaglen said decisions on how to salvage the yacht would be weeks away.
"We really don't know - we're hopeful that it's going to be salvageable [but] to a certain extent that's a decision for our insurers."
Aquos Yachts marketing manager Jim Gilbert said it would take weeks for engineers to sift through the "tens of thousands of bits and pieces" to calculate the full damage to the yacht.
"The problem with this kind of catastrophe is it's not just a matter of whether it's salvageable or not in terms of the physical aspect of the project ... the boat's been under construction for two-and-a-half years, you can't replace two-and-a-half years of blood, sweat and tears."
Gilbert said Aquos Yachts was mindful of the effects on McMullen and Wing.
"Kiwis are great craftsmen, they're very ingenious," Gilbert said.
"There's a cultural inclination for the kinds of ingenuity that go into any high-end yacht and great craftsmanship [by a] very technologically capable workforce."
It took 20 fire trucks and 90 firefighters more than 10 hours to extinguish the blaze in a shed at McMullen and Wing's Mt Wellington shipyard on Sunday.
Investigators have not yet determined what ignited the blaze, which is believed to have started in some painting products inside the shed.
Fire Service Counties Manukau area commander Larry Cocker said it was proving difficult to determine what sparked the fire, which was ruled to be not suspicious.
"[Fire investigators] may never be able to determine [what caused the blaze]. Looking around for a smoking gun can be really difficult," Cocker said.
