Nearby resident Cherrie Ellis said the ferry horn was sounded about six times.
"We heard the horn ... then there was a hell of a bang. It echoed right around the neighbourhood - we are up the hill from it on the Russell side. Then all we heard was this guy yelling so I presume maybe it was a skipper of something."
Both vessels were under motor before they crashed, she said. They were stuck for a long time as they tried to get the ferry off the yacht. Once it was prised out from under the ramp it returned to Opua with the ferry following closely behind it.
"It would have done a lot more damage to the yacht. I was really surprised to see it floating and not sunk."
Ellis said there were only about three or four cars on the car ferry at the time.
The ferry had been travelling from Russell to Opua while the yacht had left Opua and was heading towards Paihia.
A passenger onboard the ferry at the time of the incident posted on social media that she was at the front of the ferry with her kids when that accident happened and was pleased no-one was injured.
The Northland Harbourmaster has been contacted for comment.
A Coastguard spokesperson said no coastguard vessels responded to the incident.