A coronavirus-infested cruise ship had been due to call in to the Bay of Islands just one day before it triggered Australia's single biggest Covid-19 outbreak.
As the number of Covid-19 patients linked to the Ruby Princess continues to climb across the Tasman it is becoming increasingly clear that Northland dodged a ticking time bomb when the ship cancelled its Paihia visit.
When the ship docked in Sydney on March 19 all 2700 passengers were allowed to disembark without quarantine or health checks, instead dispersing to their homes across Australia.
Since then more than 620 cases of Covid-19 and 12 deaths have been linked to the Ruby Princess, making it Australia's single biggest coronavirus cluster.
On Sunday Australian police announced a criminal investigation involving Carnival Australia, which operates the ship, and government agencies involved in the incident.
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The cruise started in Sydney on March 8. After a few days at sea the vessel called into Fiordland on March 11, then Dunedin, Akaroa and Wellington.
The Ruby Princess was in Wellington on March 14 when Prime Minister Jacinda Ardern announced a ban on cruise ship visits, although any cruises already under way were allowed to finish.
The vessel continued to Napier on March 15 where passengers disembarked to explore the city and go on a variety of excursions.
A tour guide who contracted the virus from that visit is then thought to have infected an elderly relative at Gladys Mary Rest Home in Napier.
Stranded Whangārei senior citizens susceptible to Covid-19
According to the Ministry of Health, as of Wednesday 16 cases of Covid-19 in Hawke's Bay could be traced to the Ruby Princess, making it the country's eighth-largest cluster.
Four of those who tested positive were tour guides or bus drivers, six were linked to the rest home, and six were passengers.
After Napier passengers were informed the cruise would be cut short due to ''weather issues'', bypassing Tauranga and Auckland.
The ship had also been due to visit the Bay of Islands, its last port of call in New Zealand.
However, according to the Business Paihia website, the Bay of Islands visit was cancelled on the evening of March 17 — about 12 hours before the Ruby Princess had been due to arrive.
The vessel arrived in Sydney in the early hours of March 19.
Fifty-six Kiwis were on the cruise, including Napier couple Andrew and June Ranyard. They told the Herald they had ''no clue'' there was an outbreak on board the ship when they disembarked in Sydney, and were told only when they returned to New Zealand.
As of yesterday the ship was docked at Wollongong with more than 1000 crew still on board. All were isolating in their cabins with about 200 suffering respiratory symptoms, according to New South Wales police.
Carnival may also face prosecution in New Zealand with Ardern announcing on Tuesday that qshe was seeking advice about whether the company had broken the law.
The captain had assured the local medical officer of health that no unwell people would be allowed to disembark in Napier, she said.
Irwin Wilson, cruise ship co-ordinator for Far North Holdings, said he had been informed unofficially when the ship left Napier that it would skip the Bay of Islands and sail straight back to Sydney.
However, confirmation from the ship's agents came only the night before the scheduled visit.
Asked if Northland had dodged a bullet, he said it was easy to be wise in hindsight.
''At the same time we still had thousands of passengers flying in to the country with similar risks.''
The ship would not have been allowed to unload passengers without approval from Northland's health authorities, Wilson said.
Australia's 7 News reported that when the vessel arrived in Sydney on March 8, after the previous New Zealand cruise, 158 passengers were sick and 13 had a temperature.
Those passengers disembarked but the 1000 crew stayed on board while another 2700 passengers got on the ship.
The previous cruise called into the Bay of Islands on February 27. It is not known if the Ruby Princess was carrying Covid-19 at that time.
The incubation period of the virus is up to two weeks so those cases, if any, would have emerged by now.