At 2.11pm, it will be exactly one year since Whakaari erupted, coughing up acidic sludge, ash and noxious gasses.

About 100 people gathered for a dawn service in Whakatāne in honour of the 22 people who died.

Local iwi Ngāti Awa facilitated the dawn service at Whakatāne Heads.

Those gathered performed karakia and sung emotional waiata, facing the ocean in the direction of Whakaari.

Among the crowd was former tour guides Kelsey Waghorn and Jake Milbank, who were New Zealand's only survivors of the eruption.

The dawn event will be followed by a service at Mataatua Marae and a public ceremony later today.

All those who died on the island were brought home eventually, except for two who remain missing: Australian teenager Winona Langford and New Zealand tour guide Hayden Marshall-Inman.

For Hayden's brother Mark, that is still something they are getting to grips with.

"One year's a tough one because one year on we still don't have Hayden back.

"When you look back you still think that he's going to give you a call.

"You hear about an eruption on the island or you hear about activity on the island and you think everything's ok because Hayden will give you a bell, he'll let you know and I guess that call never comes through."

If the weather allowed, the Inmans would head to Whakaari the morning of the anniversary.

They planned to spend a couple of hours with Winona and Hayden - finding time to share a drink.

"Hayden's favourite drink was a Steinlager, so that's what we'll do, we'll go and give him one, we always tip one in the ocean when we're there for him."

Winona's brother Jesse Langford is the only member of his family to survive the eruption, both his parents also died on the island.

Mark Inman said he did his best to make sure Jesse could stay connected with Whakaari.

"It's his sister who's out there, you know, hanging out with Hayds, so we're in regular contact with him and his uncle.

"Every time we go out to Whakaari and find a little bit of WiFi we try and give him a live feed and show them how the island is and how she's looking, checking up so they can see where Winona is."

Inman said he felt privileged to be so close to the island and Hayden.

Every month on the ninth, the family gather at Ōhope Beach, looking out to Whakaari, on a special seat made of wakeboards in Hayden's honour.

These are the special moments he chose to remember of the past 12 months, Inman said.

If he could talk to his brother, he said he would tell him they loved him, they were here, trying to do the good that he used to.

Mark Inman laughed as he said his brother, a man of few words, would probably say "chur bro" in response.

With the borders closed to international survivors and families of victims, Whakatāne locals bear the weight of the occasion.

Ngāti Awa are holding an official commemoration with a minute's silence at Mataatua Marae while the public can gather at an event across the road.

Pilot Mark Law remembered seeing the sky darken around Whakaari 12 months ago.

He said he knew he had to act.

Along with four other helicopter pilots, he landed as the ash fell.

"I went to every single person except one on the island, so at that stage there were 20 people - I didn't know that - but that was the number.

"So Winona was the only person I never actually went to."

Law said he hoped that it was some level of comfort for them, and their families.

"If I was in that situation, it would be unreal to have someone who actually arrives after being involved in the blast and the darkness and the ash and crying out and there's no one there.

"To actually have someone turn up, it would be an awesome feeling, I'm just glad we were here, that we could do that."

He said if he could change anything, it would be that no one got hurt, and that they were not grounded and could go back to collect the six people that remained on the island.

Law has not been back since and does not know when he will.

Source: RNZ