A photo has emerged showing the scale of the backlog of ships waiting to get into Ports of Auckland this morning as unprecedented and unexpected demand sees container ships stuck at sea with goods for an average of eight days.

Up to 11 container ships were anchored in the Hauraki Gulf waiting to be processed at Ports of Auckland at the weekend, but Ports of Auckland general manager of communications Matt Ball said that had now reduced to six.

The ships currently anchored are one bulk carrier, one car ship and four container ships carrying a wide range of goods which could likely include some Christmas presents.

All three upper North Island ports were busy and there were a further five ships at anchor waiting to go into Northport near Whangarei and five waiting to go into Tauranga, Ball said.

Yesterday the biggest container ship to ever berth at Northport, the 261m-long Constantinos P carrying 1340 containers, arrived. Up to 1000 trucks - travelling either at night or during off-peak traffic times - could be needed to move the cargo between Marsden Pt and Auckland from Thursday.

Ports of Auckland had already recruited an additional 15 people to help them process the containers more quickly and hoped to have one extra crane crew in place before Christmas.

"Our biggest problem is that we don't have enough trained staff to handle the extra demand," Ball said.

It was also ramping up the use of its robot straddle carriers help move more freight.

Prior to Covid, it was uncommon for Ports of Auckland to have any ships waiting to be unloaded and on the odd occasion when it did there would only be one or two at a time, he said.

"I think the largest queue previously has been when Brown Marmorated Stink Bugs were discovered on board car ships, which resulted in quite large delays to car imports. So this sort of thing only happens in exceptional circumstances, as we have this year with Covid."

Ball said the delays were not unique just to New Zealand and were happening worldwide.

Demand between Asia and the US had also grown by more than 20 per cent, while New Zealand was facing "unprecedented and unexpected" demand.

The demand was expected to continue into 2021, with more than a month of back orders from manufacturers in China waiting to be shipped.

Last month, the Herald was contacted by a number of frustrated readers who told how they had been waiting for between four to six months for furniture to arrive from overseas as retailers including Freedom blamed impacts from Covid for delays at the ports.

Other retailers have also had to apologise to customers as the delays mean their pre-ordered stock won't arrive before Christmas.