Police have visited boats moored around Great Barrier Island, including a large yacht with a number of people self-isolating onboard, to ensure people are not flouting the coronavirus lockdown rules.
The Herald understands some New Zealanders had gone to the Hauraki Gulf's largest island to spend the coronavirus lockdown period on their boats or at holiday baches.
The usual population of the island is 939, according to the 2013 Census.
A police spokeswoman said police were aware of a large yacht with a number of people onboard which had been anchored off the island with permission from the Harbour Master.
"They are fully self-contained and have been spoken to, to ensure they are aware of the current restrictions and will not be coming ashore," the spokeswoman said.
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"Police have spoken to a number of occupants of boats that have arrived recently, and many of them are people who visit the island every year and stay for an extended period. Those spoken to have been reminded about the current restrictions."
Police said those on the island, whether on their boats or in houses, have been asked to stay there for the whole lockdown period, in line with the rules everywhere else in the country.
"We will continue to monitor the situation and speak to those seen out in public to educate them about the restrictions and ensure they have an essential reason for doing so," the spokeswoman said.
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Meanwhile, passengers who cannot show proof of address indicating that they live on the island are being barred from flying on Barrier Air.
The airline says it introduced the strict processes to ensure no unauthorised people get to and from the island.
"Barrier Air has had a strict process in place since the day of lockdown which requires anyone flying on our airline to provide a proof of address on Great Barrier Island," said Barrier Air chief operations officer Grant Bacon.
"We also call our passengers prior to their travel to confirm their reason for travel and confirming their address."
He said the airline would no longer fly tourists - even if they were Aucklanders - over the lockdown period.
"From this morning, we are only flying freight and critical industry workers to the island," Bacon said.
"Our flight today only has freight [and] we will be screening these critical workers also prior to flying."
Auckland Mayor Phil Goff yesterday said Auckland Council would guarantee one flight a day to ensure products, services and essential workers got to the island during the national lockdown period.
The daily flight will be paid for by the council, but it would be reimbursed by the Government possibly through the National Emergency Management Agency.
Barrier Air will operate the flights and will deliver 1.2 tonnes of goods every day, the mayor said.
About 950 people live on the island and its median household income levels were below that of Auckland.
Since March 24, all public transport including rail, ferry and bus have been free but restricted to essential workers and those needing to access essential services.
Passengers using ferry to travel to Great Barrier Island and Waiheke can only go on their vehicles and must remain in them for the entire voyage.
To comply with New Zealand's lockdown restrictions, ferry operator Sealink is operating on a reduced timetable and providing essential services access only on services to Waiheke, Great Barrier Island and east Auckland's Pine Harbour.
Fullers was providing free travel for people working in essential services or needing to access essential services on it's Waiheke, Devonport, Hobsonville Point, Beach Haven and Half Moon Bay routes.
The New Zealand Transport Agency said free public transport access would protect staff by removing the need to handle cash.
The free public transport was available only for those working in essential services, for medical reasons, to access essential services including the supermarket, and to move essential goods.
"It also ensures free transport for essential workers requiring access to their jobs and for the general public using public transport to access essential services," the agency added on its website.
The chair of the Great Barrier / Aotea Local Board, Izzy Fordham, told RNZ an estimated 50 boats were anchored in one harbour alone.
She said they were a burden on limited resources and police were investigating.
"Us locals were all trying to do the right thing, stay home, live within our bubble because if we get to the stage where we have community transmission of this disease and this sickness, goodness knows what it will do to our island," Fordham said.
Boaties were being "totally irresponsible", she said, because they could spread coronavirus.