Family members and loved ones of Wahine disaster victims and survivors are gathering in the Muritai School hall in Eastbourne for services commemorating the 50th anniversary of the tragedy.
About 100-200 people have arrived for the commemorations, wearing lanyards with labels such as "passenger" and "family" on them.
Lower Hutt Mayor Ray Wallace opened the ceremony by welcoming survivors of the disaster.
"I'm told that even after all these years some survivors still have great difficulty in coming to terms with what happened to them and others around them on that fateful day," he said.
Wallace said it was appropriate to begin the day of remembrance in Eastbourne, where so many passengers died.
"It was the community who responded to the events happening here on the beach in 1968. They worked hard to pull survivors from the raging surf and transfer them to safety."
One of those was John Marryatt, who had the grim task of clearing a way to Eastbourne after the tragedy and checking for dead bodies on the way.
He was working for what is now called the Greater Wellington Regional Council.
Marryatt and a doctor he never knew the name of drove the coast road to Eastbourne in a Land Rover with a bulldozer clearing the way in front of them. They stopped at each bay so the doctor could get out to check if the people on the shore were alive or not.
Over the next few days Marryatt had to collect the bodies, sometimes needing to pull them out of tightly wrapped seaweed.
When asked what the remembrance day meant to him, Marryatt began to cry and was unable to speak for a moment.
"I can't really describe it. Just as well I didn't have to get out of the Land Rover, that's all I can say."
Susan Madarasz was on the boat with her new husband during their honeymoon when the pair became separated in the chaos.
Aged 21 at the time, she found her way to Eastbourne after several hours and sent an urgent telegram to her parents telling them that if her husband called, they should let him know she was safe.
Madarasz brought a copy of the telegram as a memento to the service today.
Scott Barr supported his father, a Wahine crewman, at the dawn service.
"He told us he was last off the boat with the first man," Barr said.
He said it was "pretty surreal" to be at the dawn service 50 years after the disaster.
"Seeing the old fella all worked up ... he went and got all his memorabilia and bits and pieces."
Barr said it was "great" to see everybody at the service today.
The rainy morning reminded him of what the weather might have been like on that day, or "just gives a taste I suppose".
Transport Minister Phil Twyford said he was 4 years old when his family gathered around their old black and white TV to watch grainy pictures of the chaos unfolding in Wellington that day.
"Even as a 4-year-old, what I saw on TV that day and the effect it had on my family as the story unfolded will never leave me," he said.
He said the loss of the Wahine had changed the way ships were built worldwide.
One of the factors contributing to the ship capsizing was the build-up of water on the deck, he said.
Now ships around the world are built to stay afloat despite hull damage.
Several hundred people are crammed into the hall watching as wreaths are laid. The dawn service begins a day of commemorations on the 50th anniversary of the Wahine disaster.
Of the 734 people on the ferry, which sank in the entrance to Wellington Harbour on April 10, 1968, 51 died at the time. One died of injuries weeks later and another in 1990.
Since many of the survivors are now elderly, today's anniversary would probably be the last big national remembrance day for the disaster, Wahine 50 Charitable Trust chairman and former Defence Force chief Rhys Jones said.
Governor-General Dame Patsy Reddy and Prime Minister Jacinda Ardern will attend some of the events.
The Wahine disaster led to the creation of the Wellington Volunteer Coastguard and an air rescue service. An "Are you prepared" display, organised by the Search and Rescue Council and the trust, will highlight the importance of rescue services.
Governor-General Dame Patsy Reddy unveiled a new surf lifesaving boat and officially opened the display this morning.
"As we reflect on the events of that day, we also reflect on the lessons that we learned, lessons that have made New Zealand so much better prepared for times of extreme emergency," she said.
BP New Zealand donated the Inflatable Rescue Boat (IRB) to the Capital Coast Callout Squad as part of today's commemorations.
BP corporate and external affairs manager Leigh Taylor said BP began its partnership with Surf Lifesaving NZ after members of the Worser Bay Surf Club took their surf boat Miss Europa out in the stormy sea to help rescue people from the Wahine.
Since the partnership began, more than 50,000 lives have been saved at beaches around the country, and more than 20,000 of those rescues involved an IRB.
Wellington mayor Justin Lester also spoke at the unveiling, labelling the day of the disaster a "day of great tragedy, of courage, and heroism".
"At the time it was almost inconceivable that so many people could perish so close to shore, not far from Seatoun.
"As I woke this morning at 5.35am and I heard the rain lashing the windows across the northern hills of Johnsonville, I reflected on what it must have been like for those on the Wahine that morning."
Today's Wahine commemoration events
• 6.30am - Dawn service at the Muritai School hall in Eastbourne
• 7.30-8.30am - Wellington Community Choir sings tunes reminiscent of those sung by passengers on the stricken ferry and in its lifeboats. Wellington Railway Station
• From 8.30am - Wahine display of student works, photos and memorabilia. Muritai School, Eastbourne
• 10am-8.30pm - Wahine exhibition and talks. Wellington Museum, Queen's Wharf, Wellington
• 11.30am-4.30pm - Search and rescue display, Shed 6, Queens Wharf
• 11.30am-noon - Remembrance at Wahine mast memorial, Frank Kitts Park, Wellington central city waterfront. Orpheus Choir performs choral tribute
• Noon-12.45pm - Flotilla of about 40 vessels, including some that were involved in the Wahine rescue, steams past the city mast memorial
• 3.30-5pm - Wahine display and afternoon tea, Seatoun School
• 5.30pm - Annual NZ Search and Rescue awards ceremony (invitation only). Shed 6.
• For more information, visit Wahine 50 Trust wahine50.org.nz