Seven Sea Seas Explorer forced to anchor outside New Zealand's waters after failing biofouling standards again

Biosecurity New Zealand has ordered the operator of a cruise ship to clean its hull before continuing a voyage around Aotearoa.

A number of ships have entered our waters carrying high-risk organisms on their hulls. Now, the Seven Seas Explorer has had a cruise disrupted for the second time this summer.

The five restaurants on board the Seven Seas Explorer boast any number of seafood delicacies, but it's the oysters on the hull that are frustrating Biosecurity New Zealand.

"There has to be a layer of assurance across it when work's done to make sure that the hull is clean and unfortunately on this occasion it's found out that the hull was not clean enough for our very very high standards, our world-class standards in fact," said Biosecurity NZ's northern regional manager Mike Inglis.

On Thursday the Seven Seas Explorer departed Auckland on a 14-day luxury cruise that was meant to take in the sights of Aotearoa's coast before crossing to Sydney.

Instead, it's been forced to anchor 22 kilometres off Tauranga, outside New Zealand territorial waters, with passengers who paid $20,000-plus onboard, while cleaning goes ahead.

"The risk for us is if invasive marine pests come into New Zealand it will be very, very difficult to eradicate them. So that's why we focus on our offshore cleaning standards so when they come into our environment that everything's in good working order," Inglis told Newshub.

Pictures show the second dive survey carried out in Auckland Thursday before the Seven Seas Explorer's departure. They show tubeworms, barnacles and high-risk oysters.

And despite it being Seven Seas Explorer's second run-in with biosecurity, Inglis believes "they are taking it seriously".

A statement from Regent Seven Seas Cruises said it's committed to minimising its impact on the surrounding environment.

The cruise company added it understands and apologises for the inconvenience, frustration, and disappointment this disruption has caused to their valued guests.

Guests have been offered compensation.

Once it's been verified that the ship has been cleaned Biosecurity New Zealand said it will determine whether the vessel can continue its voyage to New Zealand ports.