Three people rescued after Manly ferry crashes into yacht

A Manly ferry has struck a private yacht in Sydney Harbour, throwing three people overboard.

A Manly ferry has collided with a private yacht in Sydney Harbour. Source: Seven Network

Three people have been rescued from Sydney Harbour after they were thrown overboard when a Manly ferry crashed into a private yacht.

The collision happened about 2.40pm on Saturday near Fort Denison and involved the "Narrabeen" vessel.

Three passengers went overboard during the collision, a Port Authority of NSW spokeswoman told AAP.

One patient suffered a chest laceration, the second was treated for a leg injury and the third was experiencing chest pain, according to a NSW Ambulance spokesman.

At least one patient had been transferred to St Vincent's Hospital, however the spokesman wasn't able to provide any details about the age or gender of the patients.

It's the third incident involving a Manly ferry in just over three months.

In mid-September, the "Ocean Wave" vessel hit Manly Wharf at low speed, leaving four or five people with minor injuries.

At the time, the company said it was not clear how the accident happened and crew would be tested for alcohol and drugs.

At the beginning of December, a packed Manly ferry crashed into Circular Quay and two people were injured.

The company has been contacted for comment.