"The sheen is about 4km long and between 10-60m wide. It is part of a larger, lighter sheen that is stretching about 10km from the wreck," he said.
Oil containment booms were set up at Maketu, Little Waihi and Waitahanui on Wednesday.
"I guess it's sad that we have to put our booms up. Kids are wondering what's going on," Miss Bennett said.
One of the challenges of the oil spill had been communicating information among locals, she said.
It was not possible to reach every member of the community with just one form of communication - "usually the email network that we've established is what we've relied on".
Volunteers were on call locally and in Rotorua, Hamilton and as far away as Waiheke Island, should the oil hit, she said.
"We've still got our core crew of local people and a big network of volunteers from our relations."
Local woman Jayne Ivimey said it was a beautiful day in Maketu yesterday and the sea was a turquoise colour, making it hard to believe an oil slick was headed straight for them.
However, she said the community was prepared, with the co-ordinated clean-up response run by the "amazing women of the marae".
"We're really well set up, we've all got our jobs now," she said.
Maketu volunteer fire brigade fire chief and owner of Maketu Beach Holiday Park Shane Beech said the community was waiting to see what happened.
"Hoping for the best and planning for the worst, sort of thing. Touch wood it doesn't come here and turns around and heads to China," Mr Beech said.
The camp had emptied out quite a bit as people went back to work, but the beach looked inviting yesterday.
"No one's really down here to enjoy it. I think people probably are concerned about it being in the water. Tell them to grab their bikinis and picnics and get down here," he said.