E Squadron brave six per cent chance

A retrieval team has brought back six bodies from the eruption zone on New Zealand's White Island.
A retrieval team has brought back six bodies from the eruption zone on New Zealand's White Island.

Hundreds of personnel were involved in Friday's astonishing body retrieval operation on White Island.

In the end, it came down to six men and two women from the New Zealand defence force's "Explosive Ordnance Disposal team - or E Squadron - setting foot on Whakaari's otherworldly surface completing the mission.

"It was unique," Colonel Rian McKinstry said.

"The conditions and terrain on the island were difficult (and) they were challenging from the point of departure."

McKinstry lifted the lid on many elements of the military mission after his team successfully uplifted six of the eight bodies police believe are on the island.

Police and Defence Force chiefs, utilising data from geological monitoring agency GNS Science, ticked off on the plan on Thursday before the Friday morning mission.

The latest seismic information was that tremors were down on the previous evening, but still drastically higher than the lead-up period to Monday's deadly blast.

"Our assessment in consultation with GNS Science was that there was a six per cent chance in any three-hour period that the volcano may erupt," McKinstry said.

"That met our threshold, our work and safety requirements. It was safe enough to put people on the island."

And so on they went, guarded from the elements wearing bright "personal protective equipment" to make them look like astronauts.

"To paint the picture for you, it's a yellow hazmat suit with a hood," McKinstry said.

"It has a closed circuit breathing apparatus system, a gas mask, so the operator while they're on the island can operate within a closed system and be protected from any gases."

With two operatives staying on the jetty with the rigid inflatable boat deployed from police vessel Deodar, the other six paired up and headed off to the crater.

The bodies were strewn in a 200 square meter period around 300 metres from the crater's edge.

The walk was taxing, given the protection required from the brutal volcanic conditions.

The men and women wore military undergarments, with a sealed, nomex light material as a mid-layer, all underneath a raincoat-style material.

Great care had to be taken traversing the rocky terrain due to the tearability of the fabric, and the reliance on oxygen tanks.

Those systems contained enough oxygen to allow a trip of up to four hours on White Island before returning to the nearby navy vessel, the HMNZS Wellington.

But owing to the incredible heat, the operatives took a trip back to the jetty amid the uploading of bodies so they could continue at full capacity.

There was another team of eight, stationed on the nearby HMNZS Wellington, ready to go as back-up.

Those soldiers were far from the only people involved in Friday's operation.

Prime minister Jacinda Ardern listed a great number of supporting agents - defence, medical, police, St John, GNS scientists among them - after meeting them.

"They were humble people, they were true professionals and they carried out their role with dignity and respect," she said.

"Although the best science, the best information available was used to make sure we looked after them, there was of course a huge amount of courage required to do what they did today.

"I hope the time comes when we can all pay tribute to what we've done today.

"My job, on behalf of New Zealand is to say thank you."

Australian Associated Press