There have been 19 new cases of Covid-19 in managed isolation - all mariners in isolation - and none in the community reported today.
In a statement, the Health Ministry said the country's total number of confirmed cases is now 2499.
Sixteen of the mariners had arrived in Lyttleton on the Playa Zahara vessel on 13 July. They were previously reported as being under investigation and are now deemed as current cases.
The ministry said daily health and welfare checks would continue for all crew who remained onboard the Playa Zahara in quarantine in Lyttelton.
The other three cases were detected in surveillance testing of mariners, who arrived in Bluff on the MS Mattina vessel on 18 July.
There was also one historical case of Covid-19 in a recent returnee in managed isolation today.
Two previously reported cases have now recovered, bringing the number of active cases to 80.
Cases onboard Mattina
Whole genome sequencing from nine crew members of the Mattina last night confirmed they have the Delta variant.
The three additional cases onboard the Mattina today brings the number of cases on the vessel to 15.
The ministry said all crew who have tested positive would remain quarantined on board the vessel and would not have direct contact with any port staff while maintaining minimal functions.
Meanwhile, three crew members, including the ship's captain, who have all tested negative for the virus, have been taken to onshore isolation facilities.
The ministry said the captain was transported last night to a secure DHB-provided facility to isolate while two of the other crew members were being transported to a Christchurch-based quarantine facility today.
Quarantine-free travel with Australia on hold
Today the New Zealand government announced it is pausing the travel bubble with all of Australia for at least eight weeks as the Covid-19 Delta variant continues to spread in the country.
New South Wales is struggling to control its outbreak of the more infectious variant, and today recorded its highest daily number of cases at 136.
For the next seven days there will be managed return flights for New Zealanders from all Australian states and territories that will require proof of a negative pre-departure test.
Additionally, those who have been in NSW will still have to go into MIQ for 14 days, and those who have been in Victoria must self-isolate upon return and have a negative day three test.