The iconic 20-metre party boat set sail for Sydney Harbour six years ago, but still holds a special place in many people's hearts.

Owner David Lazarus received the sad news while on a South Pacific cruise.

"We got the news while we were in Vila and flew straight back. The skipper was reversing into the dock (near Gladesville Bridge), when it hit a pier, which pierced a hole in the hull.

"Being made of wood, she sunk within half and hour and has already been deemed a write-off.

"I'm absolutely devastated, just gutted, but thankful that there were no customers on board at the time and that no-one was injured," he said.

The Port Venture, which was more recently known as The Venture, was built in 1984.

It graced the Hastings River for more than 24 years before being purchased by Mr Lazarus and joining his fleet of party boats near Sydney Fish Market.

More recently, The Venture was relocated to Cabarita and was popular for its weekly bingo cruises and weekend functions.

The recovery of the 31-year-old boat will be a mammoth operation requiring a crane and floatation devices to bring it to the surface.

Since Sunday's tragic accident, Mr Lazarus said he has been flooded with messages of support from friends, locals, loyal customers and well-known personalities who have entertained on the boat.

"She certainly held fond memories for a lot of people.

"Over the years, we've had lots of Port Macquarie people travel to Sydney for a cruise because they had so many good memories of the Port Venture," he said.

nicole.langdon@fairfaxmedia.com.au