The group was told it had to raise $12,000 as security against costs in its battle against the council over the decision to close the Marine Parade facility.
The sum is about a third of what it is estimated the total cost of legal representation for a full judicial review will be.
One of the driving forces behind the action and fundraising, Emily Otto, said the group was thrilled "and relieved" to have reached the fundraising total in such a short period.
Achieving it in only two months showed the support "out there" and that people wanted Marineland retained as a marine hospital and eco-education centre.
"We are absolutely not going to give in on this," she said.
"I have been confident we will be successful since we started out.
"We have been out and we have been talking to people - I don't think the council has done that - and the public is telling us they want it back."
Mrs Otto said the group realised it was facing a hard fight, but getting past the first step of setting up the judicial review had boosted members' resolve.
The council initially tried to halt the group's quest for a review but was over-ruled.
It would now be required to file affidavits to the court and the Marineland group would be called to respond.
Ms Woodhams said she believed it would be a long process, but the group was committed.
"It is another step and it puts more pressure on the council - people are starting to ask questions."
She believed the city had fallen behind other centres in provision of attractions for families and children.
"Marineland made Napier famous and it can do that again as a marine and eco-education centre," she said.
"You cannot underestimate the value something like that has for children."
Mrs Otto said the animals still inside could be heard but not seen.
"It's heart-breaking to hear them," she said.
Approaches to have the facility opened to the public during school holidays had been turned down.
This year, a council spokesman said opening Marineland "was not an option that is available".
