"It was a low-stress incident. She landed very smoothly in the lake. It was very controlled," she said.
The pilot was expected back at work today.
Mrs Vroom said she was not able to say what caused the pilot to make the move as the incident still had to be investigated by Volcanic Air Safaris and the Civil Aviation Authority.
Emergency services were called to Lake Rotorua to deal with the incident about 10.15am.
Rotorua police communications manager Kim Perks said a local who witnessed the crash landing waded out to help the pilot and passengers out of the aircraft.
A boat in the area took the four people to Volcanic Air Safaris' base at the Rotorua Lakefront.
Ms Perks said the Civil Aviation Authority was securing the scene and investigating.
Rotorua Fire Service senior station officer Colin Rolfe said it appeared the pilot did a fantastic job landing the helicopter safely.
"It landed upright on its skids," he told The Daily Post.