A homemade hovercraft has left bystanders stunned and drawn international attention to the work of a Top End pilot.

Key points: A video of a hovercraft zooming in Darwin Harbour attracted social media attention

A video of a hovercraft zooming in Darwin Harbour attracted social media attention James Greenberger built the hovercraft in his carport

James Greenberger built the hovercraft in his carport He is a commercial pilot with an interest in anything that flies

Since being posted on ABC Darwin's Facebook page just over a week ago, video of James Greenberger's test flight has been watched more than 939,000 times and attracted thousands of comments.

"It's been a huge response," he said.

Mr Greenberger has also gained the respect of the hovercraft hobbyist community.

"They're all really happy with the craftsmanship and the speed that I've done it. They have said it looks like the fastest hover wing ever built."

Mr Greenberger, who is also a commercial pilot in the NT, said he got the idea of building hovercraft after developing a love of aviation at an early age.

"I just love anything that flies," he said.

But it was a while before he could start building his dream.

James Greenberger said sourcing materials was one of the greatest obstacles in the project. ( ABC News: Chelsea Heaney )

"I just remember, back when I was 12, I wanted to build this hovercraft called a Pegasus. It was just a round, plywood disk with a lawn mower engine," he said.

"I asked my dad to build it and he said no because it was too unsafe."

"So for many years there were no more hovercraft, and it was probably another 15 years to get into it after that."

But on a recent sunny Saturday morning in Darwin, Mr Greenberger saw one of his biggest projects take flight — and there were plenty of people out on Darwin's coastline to witness it.

Many of them took to social media to express their reaction to the sight.

Well you scared the living daylights out of us. First time we were all sitting there stunned. Second round we all had our cameras out ready! — Rebecca McLean

Is it a bird, is it a plane? No it's a … it's a … all right what the hell is that?! — Fiona Bond

Great to see someone with an idea and the drive to actually build something from scratch, hope I get to see it up close one day — Tony Henderson

Saw this whilst riding my bike up to East Point! — Bobbie Wilkes-Brimage

Materials the biggest obstacle

Built piece-by-piece from 2D technical drawings in his carport and at the Palmerston Men's Shed during the humid Top End wet season, Mr Greenberger's project needed a lot of workshopping and hand crafting over the past 11 months.

The flying boat was made by hand out of fiberglass. ( Supplied: James Greenberger )

"I had to learn how to fibreglass, which I hadn't done before," Mr Greenberger said.

"That was a bit hard in Darwin because fibreglass goes off in half the time that it does elsewhere because it is very hot."

"But the biggest troubles were trying to get materials up here."

Although there were hurdles in the construction phase, the pilot had little trouble getting his creation out on the water, due largely to the Northern Territory's maritime regulations.

"On the testing day, there were two police watching it all unfold, and by the time I was ready for the test there were eight officers up there," he said.

"I did approach them and make sure they were fine with everything and they said they were just Snapchatting to their friends.

"It is a watercraft, it is classified as a boat. Darwin doesn't require registration for boats and they also don't require boat licences.

"But if there are any worries, I am a commercial pilot."

The Civil Aviation Safety Authority said it did not regulate hovercraft because they were not considered aircraft.

Mr Greenberger said his partner, however, might have something to say about his new transport.

"It's been a little difficult but she understood," Mr Greenberger said.

"Every little moment I had spare was working on the hovercraft … but every now and then I brought flowers home to her to let her know I still cared, but I just wanted to see it fly."

"I think if I start anything in the near future I'm going to get in trouble … so I'll stick with this for a while, but I think there's many years of enjoyment out of it."

Mr Greenberger said he intended to give the hovercraft a fresh coat of paint and get it back out on the water.

"Once it gets a nice paint job I've got many hours of further testing and then off to go fishing in the Top End on it," he said.

"I think it is going to scare all the fish away but I'm going to try."