A tugboat with more than a century on the water came to a sudden halt when she struck rocks in Tutukaka Harbour and was left high and dry.
The Shamrock became lodged on rocks inside Tutukaka Harbour about 9.10pm on Thursday.
An Auckland couple and their dog were rescued by Coastguard in the dark.
A salvage mission yesterday morningat high tide failed to free the 13m-long vessel from the rocks. Water had made its way into the hull and was holding the boat firm.
Northland Regional Council harbour master Jim Lyle said the salvage crew would wait for the water to drain away as the tide receded and would try to fix a hole in the hull so it could be refloated on the next high tide.
However, that would be in the middle of the night and be difficult so it was likely the refloating would take place today. "It seems to be the result of a navigational error and they have ended up on the rocks," Mr Lyle said.
Calm sea conditions were helpful because there was little swell to deal with while trying to free the boat.
Mr Lyle said the fuel tanks were checked and there appeared to be no risk of spillage.
Insurance assessors were also on the scene yesterday.
"We will continue to work with the owners and put them in touch with contractors and continue to help and assist," Mr Lyle said.
Northland police Search and Rescue Sergeant Craig Burrows said Coastguard alerted police to the emergency.
Mr Burrows said the crew onboard were asked to activate their emergency locator beacon so the rescue team could find them in the dark.
The Tutukaka Rescue team then took the people and dog to shore.
"Everything was done how it should have been and the boat owners set off the beacon when requested," Mr Burrows said.
According to boat website Waitemata Woodys, Shamrock was built by Bailey and Lowe and launched in 1915.
The vessel was built for Arch McCarthy who ran the ferry service from Waitakaruru to Thames until the Kopu Bridge was opened.
She was sold to John Faulkner in 1925 where she worked as a ferry and tug in Tauranga harbour towing barges from Motiti Island and Mayor Island.
In 1980 she changed hands again and went to Kawau Island where she did tug work towing log rafts and barges during the building of many of the wharves at Kawau.
With the tides permitting she would take the locals to Warkworth to do shopping.
She was then onsold and was charter fishing from Leigh to Great and Little Barrier islands.
In 2000 she was bought by Helensville owners of Shamrock Charters and sailed to the Kaipara Harbour where she spent the next six years doing charter fishing in the harbour and over the Kaipara bar.
In 2006 an Auckland couple bought her and are believed to have been aboard when she hit rocks on Thursday.