More than 1400 children from 32 schools throughout the region had watched Mr Thatcher build his kite during the week.
Mr Thatcher said he would normally only use traditional materials to make his kite. But due to a short time frame, he used what he could.
He harvested raupo, or bulrush leaves, at his Matapihi home last year, but they were still "a bit wet" to use for this particular kite.
Toetoe also had to be harvested for over a year, so instead Mr Thatcher used bamboo.
"I managed to get that done, but not the toetoe," he said. "Toetoe dries a lot quicker, about six months.
"But I have been away from home for about two thirds of that time, so when I get home I am too tired to go and harvest my resources."
The wings of the kite were made from the aute, or paper mulberry tree.
"It is the leaf," said Mr Thatcher. "It has been processed into a fabric. They are from Tonga. You just cannot find enough aute in New Zealand because it is not part of our traditional clothing, whereas in Tonga it is a big part of traditional clothing."
Mr Thatcher was in Tonga three years ago when a local woman gave him some aute to use for his kites.
The design was based on the traditional Maori kite used for fishing.
"Omanu is named after kite flying," said Mr Thatcher. "A war party came to where the surf club is and they brought kites down.
"They flew the kites and made them look like they were swooping down towards water like birds going down to fish."
Mr Thatcher said fishermen near Mauao saw the kites and rushed to the beach with their fishing gear. "Crafty devils," he said.
Kite flying this time of year was traditional. Maori fishermen used to put messages on the ends of their kites for good luck, said Mr Thatcher.
"What you do is say a prayer on these, and you put all of your wishes on to it," he said.
"When you fly them they go up into the sky and the creator grants your wishes. That is the idea.
"That way when they were told it was going to be a lousy season this year, everybody goes out and flies their kites with their prayers on them in hopes of turning around the prediction."
But Sunday's kite flying was for families to have fun, said Mr Thatcher.
Hera Waitai from Te Wananga O Aotearoa said Matariki was a whole month of celebrations.
"It is a time when we start harvesting, when we start to plant food, it is our Maori New Year."
She said kite flying was part of those celebrations. "It is a bit of a pastime activity you used to do when you were younger.
"It is good to see the kids outside playing and what better place to be doing it than their maunga [mountain] of Mauao."
Te Puna Rangiriri Trust general manager Awhina August said the event was part of a week-long celebration for Matariki ki Mauao.
She said Sunday was the last day to celebrate as a community.
Eight workshops including presentations on navigation and traditional Maori tools were run throughout the week.
Sport Bay of Plenty was also part of the Matariki Whanau Day and held games for families which included a photo competition around Mauao.
"We wanted to come along and support Matariki," said Sport Bay of Plenty green prescription advisor Lisa Te Paa.
"We feel that anything significant to the community, especially if it is associated with well-being, we wanted to be involved in too."
