A rescue helicopter and ambulance were called to an emergency at Moturiki (Leisure Island).
A St John Ambulance spokeswoman said paramedics were treating a man at the scene. He was in a moderate condition.
She said the ambulance and helicopter were responding to an emergency call that came in at 4.57pm.
The patient would likely be taken to hospital but she could not say which at this stage.
Taylor Jakeman, 17, was with a group of eight friends when they saw a man fall near the blowhole.
She said he was climbing up the rocks nearby when he tumbled down about 5m.
"He had a gash on his head," Taylor said. "We called the ambulance and they came over. Until they came, we had to put pressure on the gash on his head with a towel.
"We had to make sure he stayed conscious. He's just been airlifted."
Taylor said it was quite scary, but the group were pleased they could help.
A bystander told the Bay of Plenty Times the Trustpower TECT Rescue Helicopter had landed on the island after hovering over it for a period.
He said there was an ambulance parked near the war memorial cenotaph and, from a distance, it appeared paramedics were trying to resuscitate someone.
"It looks like they're pushing up and down on someone."
As the crowd chanted, Seymour walked back into the Beehive with his MPs.