Four days after the Wahine disaster on April 10, 1968, a young Rotorua policeman pulled into the driveway of the Corson family home on Springfield Rd to tell them their son Stuart was missing, presumed dead, after the ferry's dramatic sinking in Wellington Harbour.
He got out slowly, put on his helmet and adjusted it, took his handkerchief out to blow his nose again, and carefully wiped his already well-polished black shoes on the backs of his trouser legs, before finally knocking on the door.
"Is this the home of Stuart Corson?" he said.
"Yes that's me," a young man answered.
The policeman's tense face burst into a broad smile as he learned that Stuart Corson's name had been wrongly recorded at Wellington railway station after the disaster, and he had in fact survived.
"He was just so happy to learn that he was not bringing news of a dead body to yet another family," Corson told the Rotorua Daily Post; his memory of watching that policeman approach the door still vivid in his mind.
Corson, a chemical engineering student at the University of Canterbury, was on his way home to Rotorua for his 21st birthday celebrations when he took the ferry from Lyttelton.
He said there was "a certain disbelief" when, 50 years ago today, an announcement came over the ship's public address system around 6.40am, stating the Wahine was aground on Barrett Reef and all passengers needed to assemble at the lifeboat muster stations.
"It had been an increasingly rough voyage and we had had the horrendous experience of the sound of the ship just graunching across the reef just metres below us in our lower deck cabins."
The Wahine was being pushed over jagged rocks by the hurricane winds and seas, leaving the underwater hull battered and holed. There were 734 passengers and crew on board.
"Coming up the stairs [to the lifeboat station] we looked out the window into an absolute maelstrom of marine fury and hell. Just beyond the ship's railing was a towering rock with waves smashing over the top of it and white foam just streaming horizontally out from it.
"Huge waves rising and falling, smashing against the boat, the wind howling and green water just surging down the deck, right outside the doorway we were looking through. You did not know what to think... But we were assured right from the beginning and right through the morning that everything was well."
Corson describes his memories as "surreal".
"We were a secure and organised country where things happened right. When the Wahine foundered within metres of the capital, things just went entirely off script."
He was traveling with a close friend, the friend's elder sister and her pre-schooler.
Corson said instinctively they went to the high side of the ferry.
"We looked down on the exposed side of the boat and just saw the sheer distance of just steel and then the seas beyond... It gave you something of the scale of the ship."
Corson realised they were starting to list.
"A young woman near us attracted the eye of the ship's cabin boy. He whispered something in her ear and she and her friends got up very quickly. That was a real signal that something was up."
Corson's group followed to the crowded lower side of the ship.
Some lifeboats were already upside down and there was a lot of confusion.
"As the crew inflated rafts, the wind would just pick them up like debris in the breeze and they would fly for half a kilometre."
He helped his friend's sister and her child into a boat, before leaping into the surging seas.
"We were well dosed in fear of World War II movies and knew we did not want to be sucked down when the ship went under. So it was a very easy thing just to step over the railing and jump into the sea."
The two students clung to an upturned life raft and began to drift away.
Corson estimates he was in the water for around an hour and a half before the raft came alongside a lifeboat.
"The boat's turning propeller came down on our life raft rope and tore it to shreds, which immobilised it. My friend and I helped get the propeller free and we were hauled into the boat somehow.
"Some of the group on the raft subsequently drifted away and went with the main surge of people across to the rocky Eastbourne coast, where some of them died... The dice fell the right way for me that day."
Corson's boat safely reached Seatoun, as captured in the photo below.
"I find it fascinating that I kept my glasses on for the whole ordeal."
It was only after Corson was escorted to the railway station and given a meal, that he realised lives were lost.
"I fortunately did not witness the deaths caused by exposure, drowning and the rocks. I was troubled but not traumatised. Through life, people have told me I was too tough, but we were young and lucky. I almost feel guilty for that.
"There is a strong case for not dwelling on it. I did not overanalyse it or reinforce the drama. We came ashore and got on with our lives."
He remembers walking away, down Lambton Quay, with a blanket on his shoulders. He was then able to call his parents.
"I could just hear the sense of relief in my mother's voice."
He watched the reports of the sinking on the 6pm news that night.
"We were asked if we wanted a refund the next day, but first we were asked if we still had our ticket."
Corson got back to Rotorua for his 21st and had an extra reason to party when he returned to Christchurch.
Six months later his suitcase was returned to him, but he had to throw all of the contents out.
Fifty-one people lost their lives that day, another died several weeks later and a 53rd died in 1990 from injuries sustained in the wreck.
Corson has had little contact with other survivors, which was an incentive to go to the commemorations today in Wellington.
The Wahine 50 Trust has planned a day of events, starting with a dawn service at the Wahine memorial in Eastbourne.
After university, Corson moved back to Rotorua.
He has a doctorate in engineering and is a Fellow of the Royal Society of New Zealand.
Corson's pioneering work on the influence of wood properties in mechanical pulping won him the Arne Asplund award in 1997, an accolade regarded as the 'Nobel Prize' in the field of mechanical pulping.