Military helicopter flights have been taking off from Kaikoura, flying tourists out of the quake-hit town to Christchurch.
The town was hard hit by a 7.5 magnitude quake, which struck near Hanmer Springs at 12.02am yesterday. It was 16km deep and has been followed by more than 800 aftershocks. GeoNet said there had been 278 quakes between 7pm and 5am.
Two deaths have been linked to the quake, and more than 20 people have been injured.
By midday, about 40 tourists had been airlifted. The Defence Force expects to make 16 flights in total today, each one taking about 12 people.People with medical conditions, pregnant women, families with children and the elderly are being given priority.
There are estimated to be about 600 to 700 tourists wanting to leave the town.
RNZ reporter Phil Pennington said those with flights to catch were frustrated with the time it would take to get out.
"I talked to a Belgian man, he said that the army should be there, he said that poiltically it's been a failure but that the marae and the local volunteeers had been very good. But he wants faster action - and that was echoed by a few people that we talked to.
"Others did say they thought it was going well - including an eight-and-a-half month pregnant Wellington woman - and they were obviously happy to get out."
Private helicopters are also flying out tourists, including Chinese tourists who had left on a helicopter chartered by their embassy.
RNZ reporter Tim Graham in Kaikoura said basic supplies in the town appeared to be running low. A queue of about 200 was outside the local New World supermarket and bread was being rationed to about two loaves per customer.
The local petrol station was backed up with vehicles.
The Red Cross is also sending helicopters to take tourists to a welfare centre north of Christchurch and St John paramedics were to be flown in to relieve crews and deliver supplies, and
Two navy ships - HMNZS Canterbury and another vessel - are sailing to Kaikoura overnight from Auckland, picking up supplies on the way, and are expected to arrive by tomorrow.
In Marlborough, heavy rain is making conditions even harder for residents, while downpours had cut major routes in and out of Wellington.
In Kaikoura, long queues were forming at the supermarket, with people taking up to 30 minutes to get into the shop to buy supplies. There were also queues at petrol stations.
Acting national civil defence controller Shane Bayley said 70 to 100 people had stayed last night at Takahanga marae.
The coastal highway is blocked both north and south of the town and repairs are focused on the inland Kaikoura road. Civil defence estimates it will take at least a couple of days work to get it open to one lane.
Prime Minister John Key told Morning Report there were no estimates on when the coast road would be re-opened. The sheer volume of material to be shifted meant engineers might have to look at realigning the road.
"When people have a chance to reflect on all of it, the scale of it, and the damage to the rail network, you can't help but wonder the transport agency won't say that some sort of realignment programme ... at least I think they'll question whether the road's in the right place."
Kaikoura's power supplies and telecommunciations service remain intermittent. Mr Bayley said landline services would be problematic for a few days and mobile communications are sporadic.
Pressure is mounting on fuel and supplies in Kaikoura. Civil Defence says only three days supply of fresh water remain.
Takahanga marae deputy chair Major Timms said the town's concrete water tank had split in two.
Marae feeds 700 after quake
The marae, which is also a civil defence welfare centre, yesterday fed about 700 people in the aftermath of the quake.
The marae provided shelter to hundreds of Kaikoura residents and stranded tourists, despite not having water, electricity or a functioning sewerage system.
Hot meals were cooked on the marae's gas cookers and Ngāi Tahu's fishing company donated seafood including hundreds of crayfish.
Adelphi Bar and Restaurant chef Jason Timms said the crayfish would normally be destined for restaurants such as his, but they are all closed, many with extensive damage.
Building inspectors and council staff from Canterbury civil defence are going into Kaikoura and will go door to door to check on people.