There were strong feelings among the crowd.
Patea's Tom Matiaha objected to a chairman's casting vote deciding whether consent would be granted.
"In my opinion the environment will be raped, both animal and mineral," he said.
It would be like the damming of the Patea River, done without thought for the piharau (lamprey) that used to be there in season.
"I haven't seen piharau here for a long time."
Te Huatahi Hawira said seabed mining was more than just a Taranaki issue and iwi should unite against it. She noted Ngā Rauru, Ngāti Ruanui and Whanganui were all represented.
"Once we open up these doors and allow them to come in they will try and mine all around Aotearoa. We will end up like Papua New Guinea."
The joint manager of the award winning South Taranaki Reef Life Project, Bruce Boyd, said the granting of the consent had hurt him and it was tough to talk. His project had showed the abundance of sea life on a reef 11km offshore.
He believed life would be equally prolific where the mining is planned. He had hoped to prove that, but was unable to get out there.
"It's just we've had the worst season ever as far as boating conditions go."
Daniel Boyd said by the time the 35-year mining consent was finished he would have grandchildren.
"I will be telling them how we used to fish here. We're going to ruin it for the sake of corporate greed."
The commodore of the Patea Boat Club said the 163 members had fought the seabed mining application, after deciding it would be very destructive and wouldn't help anybody.
Whanganui's David Scoullar said undersea mining was a dreadful backward step.
"I'm here to show some solidarity with the people of South Taranaki in their opposition."
Another Whanganui man, Athol Steward, had worked with Kiwis Against Seabed Mining and submitted at the consent hearing. He's had T-shirts printed with slogans and is planning an event in Whanganui.
"The fight is just starting, I think. This is when people will really come out and voice their concern."