Mr Holmes had been a space enthusiast for all his life, and despite travelling to Cape Canaveral once this would be the first Rocket launch he had seen.
For him to also witness the first launch from New Zealand was pretty special, he said.
Hamilton resident Johnny Zheng said stopped after seeing signs.
"I was just driving past, if it weren't for the signage I wouldn't have known it was happening."
The rocket is visible from the site, but binoculars are being handed around so spectators can see it clearly standing upright in its dock.
"When you see it through the binoculars it becomes real," Zheng said. "It's something quite unusual for New Zealand."
UK tourists Tim and Amy are travelling to Gisborne, and also stopped at the site after seeing signs.
Although they had to drive on, they were planning to keep an eye on the action as they made their way around the peninsula.
Police, fire, and St John have also set up shop in the Mahia boating and fishing club. It's understood representatives from Wairoa District, and Hawke's Bay regional Council are also there.
The agencies will be in Mahia for the duration of the testing window. Their duties range from assisting with patrol boats to communicating with residents.
Hawke's Bay Today was told no one on site could comment, as all communications were to go through Rocket Lab.
Rocket Lab's first test launch is still scheduled to blast off this afternoon.
Boats have been sent to patrol the area around Mahia Peninsula, to make sure no one tries to enter the exclusion zone.
This means the countdown clock is still ticking for launch, despite persistent rain falling on Mahia. Visibility is poor.
This will be the company's third attempt to launch their rocket from Mahia Peninsula. The previous two attempts have been called off because of unfavourable weather conditions. MetService is forecasting rain should clear this afternoon.
The company tweeted earlier today it hoped to launch between 1pm and 5pm.