New video footage shows what remains of the fishing charter vessel Enchanter after it sank in fierce seas on Sunday night, leaving at least four people dead and one still missing. 

In the footage the wreck is visible just below the surface of the water, one hull barely breaching the surface. 

The video was shot on Monday from a Westpac helicopter involved in the massive search and rescue operation on Monday. 

It shows a Navy boat involved in the rescue crossing a calm sea under a cloud-studded sky - a far cry from the ferocious thunderstorms that swept over Northland just a few hours earlier. 

Ten people were on board when the Enchanter sank amid rough seas around 11pm on Sunday. A rogue wave is understood to have hit the boat near Murimotu Island, breaking the bridge. 

Five survivors were rescued and the bodies of four people were recovered yesterday. The search continues this morning for the last missing person. 

Maritime NZ Rescue Coordination Centre spokesperson Nick Burt told RNZ this morning that person could still be on the boat, or they may have been swept away. 

The police dive squad would be playing a crucial role this morning and would look at the wreck, Burt said. 

"We need to investigate all possibilities." 

Some survivors had been found clinging to Enchanter's hull by rescuers, Burt said, though they ended up in the water as they were winched up. 

He estimated they had been in the water for about four hours before being rescued. 

"I suspect the effects of hypothermia would have certainly been kicking in by then." 

In a further statement this morning Burt said it was likely the wreckage from the Enchanter would have drifted with the current overnight, so the first goal would be locating it. 

Conditions were mixed for searchers, with poor visibility and showers, while moderate seas are forecast. 

Today's operation would be a mix of on and in the sea, with support from the air, Burt said. Three vessels, two helicopters and one fixed-wing aircraft would be involved and were heading off-shore around 8.30am. 

"While we have a number of locations of interest, we need to thoroughly check over about 500 nautical miles of ocean," he said. 

The Police dive squad would be deployed if any areas of interest were found. 

Burt told RNZ earlier the operation was still being treated as an active search and rescue. 

"We are holding out every hope that we will find the one remaining missing person." 

The Transport Accident Investigation Commission (TAIC) yesterday opened an inquiry into the incident. 

A protection order has been placed on all remains of the Enchanter to protect evidence. 

Anyone finding debris should report this to the police.