More than 500 sailors on New Zealand navy ships were exposed to tests of hydrogen bombs in the late 1950s. One sailor spoke ahead of Anzac Day.

He was a 17-year-old kid from Te Kuiti when he was ordered onto the deck of a Navy ship and told to sit down with his back facing out to sea. He and his mates donned dark glasses and wore what was grossly inadequate protection. Then he saw the bones in his hands from the flash of a hydrogen bomb being detonated.

Ordered to stand up and turn around, Tere Tahi saw what should have been a frightening sight but his reaction was one of awe and wonder.

"It was the most beautiful thing. It was fantastic. It was fantastic seeing all the different colours in the blast. It was a marvellous experience to see something like that, but we didn't know what effects it would have on us after that. We went in close to the fallout when the sea was being drawn towards the mushroom."

Tahi had joined the Navy as a teenager and was stationed on the ship Rotoiti, one of two New Zealand ships that was sent to Christmas Island and witnessed the British testing hydrogen bombs in 1958. The legacy of those tests continues to affect those who saw them and has been passed down through their families.

"We were told to get on to the upper deck with anti-flash gear, put on dark glasses and to have our backs towards the detonation and when that was completed, we were told to turn and watch the blast. We had all this gear on and dark glasses and when it went off we could see the bones in our fingers, in our hands, with our hands over the dark glasses."

"I wasn't scared, because we didn't know what the after effects would be."

"It was something that as a 17-year-old I think to myself not very many of my age group would be able to see something like that. A lot of us had illnesses through nuclear radiation, it's in our genes now, the radiation.

"Everyone has suffered. I couldn't say it gives you the proportion, but the majority of like the guys who witnessed it would have some ill effects from it. We lost a lot of our sailors."

Tahi is now the president of the Nuclear Test Veterans Association in New Zealand and has taken on the fight to try and help veterans and their families affected by the impacts of being exposed to radiation. The association is having a reunion on April 28-30 in Palmerston North.

"I've set up some projects to help our veterans that have illnesses. What I want to do is give them some assistance helping them out with the illnesses. Some of them are finding it difficult to finance."

The illnesses are not limited to the veterans themselves."Another problem that we faced with is a lot of our children, a lot of the veterans' children have been born with deformities. It's been very bad too. And that's my final legacy - if you try and do something for them."

The lack of recognition for those suffering the after-effects of military service continued on into the Vietnam War.

"Agent Orange (veterans) came to us and wanted their case put forward when we were putting our case through. And the same thing has happened to them and we're still fighting our case. Yeah, we're looking for recognition. That's what we're looking for. And I've had my latest letter that's gone to the Prime Minister to see if we can get some recognition of our involvement."

It wasn't only New Zealand personnel who were exposed to the blasts. British sailors were also present and have been waging the same war to get recognition.

"I went to England to a nuclear test veterans association commemoration. I was invited by the English government to go over there, this was in November of last year. It was the British. It was them that dropped the bomb."

He says in hindsight he believes they were being used in an experiment. He worked as a radio operator and heard the secret communications coming through.

"As a radio man we receive secret signals saying that the reason they wanted troops there was to see what effects it would have on the equipment, which would have been our ships and the equipment on the ships, and to what see what effects it would have on the men. It was terrible. They wanted to see what effects it would have on us. It was obvious we were guinea pigs.

"Hiroshima and Nagasaki, our bomb was a hundred times worse than that. A hundred times worse."

The Hiroshima and Nagasaki bombings killed more than 225,000 people. The Atomic Bomb Casualty Commission was then established to undertake epidemiological and genetic studies of survivors, following approximately 200,000 people for more than 70 years. But no equivalent studies have been carried out on military veterans.

An estimated 20,000 British servicemen, 524 New Zealand soldiers and 300 Fijian soldiers were deployed to “Christmas Island” from 1956 to 1962.

Between May 1957 and September 1958 the British government tested nine thermonuclear weapons on Kiritimati for Operation Grapple. In 1962, the UK cooperated with the US on Operation Dominic, detonating another 31 bombs on Kiritimati.

The long-term impact on their lives and families largely hasn't been formally acknowledged. The inhabitants of the islands have never been acknowledged either.