Lake Macquarie MP Greg Piper and deputy CEO of Lake Macquarie council, Tony Farrel, joined Johnson Property Group's Keith Johnson for a ribbon-cutting ceremony to mark the occasion.

Mr Johnson, who first began planning the Trinity Point development in 1999, said the marina opening was a significant step in the $388 million overall project.

"Today's really a milestone for this development," he said.

"It's the old story, people just don't like change. But look, it's got well supported, it's approved now and we're up and running today."

The veteran property developer said the project had not been without its hurdles but he was pleased to see the marina in operation.

"It's been really hard," he said. "Twenty years. Just to get the studies done to get the marina approved cost $4.7 million. Had I known [that] back then, we never would have started.

"It's a great feeling to see the project. You set a vision, and to see it actually come to fruition, is pretty exciting.

"But also to the people in the community that we committed to, to making it happen, it's now happened."

The first stage features half of the 188 approved berths.

A planned helipad is still in a court process but stage two will not be built until the extra berths are required.

Mr Johnson said that might not take long as interest was strong ahead of a restaurant opening, and apartments hitting the market, in September.

He is confident the community will embrace Trinity Point after seeing the marina.

"I have no doubt that they will," he said.

"This will be a hub, a meeting place for the community.

"It's not an exclusive [area] just for the people who own here, none of these businesses will work without being part of the community."

Former Lake Macquarie mayor and local MP Greg Piper said the project had been "quite a challenge" for the developer, council and community over the years.

"It's got to the point where the developer is providing what council sought," Mr Piper said.

"We zoned it for tourism and this what he's providing. I have to say, everything out there is first class.

"I think people going out there will be very, very pleased in the way in which it is being delivered."

Mr Piper said the opening of the restaurant later this year could be "what locals down here are awaiting for".

"If the development's going ahead, they want to be able to use it," he said.

"And the way most people will use it, is to be able to enjoy the foreshore, the park around the council reserve we got there and also the other amenities.

"Most people won't be bringing their super-yachts in there, but hopefully they'll certainly enjoy the rest of the amenities."