Authorites have let strip over the vandalism of a local landmark.
Unimpressed local maritime staff say the dab hands who repainted the historic Hokianga Harbour navigation marker with the local rugby strip are potentially endangering lives.
The East Cardinal mark, a riveted cast iron structure on Takataka Rock at the northern end of the Hokianga Harbour's Narrows, is supposed to have a black top and bottom, with a yellow middle: an internationally recognised colour system to assist with safe navigation.
Regional harbourmaster for the Northland Regional Council Jim Lyle said the beacon - a white light thjat flashes three times every 10 seconds - has been helping vessels navigate in safe water to the east for many years.
However, someone had repainted it white with a blue stripe sometime over the past few weeks.
Lyle said the motivation for the prank was unclear, although he had been advised the beacon's new unauthorised scheme "happens to be the colour of the local rugby team".
He said the repaint was noticed and reported by the Coastguard during a training trip. The stunt might seem funny to some but his office took a very dim view of it, Lyle said.
"The matter had been reported to police, who have been asked to assist in finding whoever was responsible.
"There are a number of issues associated with the illegal painting of the structure, the most important being the risk to safety of mariners."
Lyle said it was an offence under the council's bylaws and the Maritime Transport Act to damage or deface an aid to navigation and those responsible could be fined up to $10,000.
The council has issued a formal navigation warning through the local Coastguard radio station to warn harbour users about the incorrectly coloured beacon and faced "significant" costs of many thousands of dollars to repaint it.
"Unfortunately we can't just slap more paint over the top of an unknown paint," he said.
"Painting structures exposed to salt environments requires correct preparation, and high quality paint systems."
Lyle said removing the paint was also quite difficult as it would depend to some extent on favourable weather. Scaffolding would also be needed as the marker could only be accessed from the water.
Equipment would have to be ferried to the rock on suitable vessels - just before the maritime team's busy summer season starts.
Lyle said the council would try to recover some of the extensive costs from any offender who could be identified.
Meanwhile, he said the council will take advantage of the forced repaint to do unrelated engineering work on the structure.