The family of a Kiwi man killed by pirates in Panama have released "beautiful yellow flowers" into the Caribbean Sea in a memorial to the much loved husband, son and brother.

Alan Culverwell, 60, died last week when pirates shot him at close range after using the cover of darkness to board his family's boat, the Aqua Lobo.

Despite suffering a machete-blow to the shoulder, Derryn Culverwell battled to lock herself and their twin children in the boat's cabin, inset. Photo / Supplied

Despite suffering a machete-blow to the shoulder, his wife Derryn Culverwell managed to lock herself and their twin children in the boat's cabin and made an emergency call to New Zealand to raise the alarm.

Derryn Culverwell has subsequently been treated in hospital and spent time helping investigators piece together the crime.

But today she was able to make an emotional return to the boat for the first time since the attack five days ago to retrieve belongings and honour her husband.

"They were able to say a few words and leave some flowers floating behind the boat as it left port," Culverwell's sister Derryn Hughes said.

The flowers were the idea of Culverwell's parents, who had felt "helpless" back in New Zealand, unable to comfort and "hold their grandchildren", Hughes said.

Alan Culverwell died in Panama while protecting his wife and young children. Photo / Facebook

Yellow flowers were chosen because this had been the favourite colour of Culverwell's beloved grandmother.

The small ceremony was a great comfort to Culverwell's grandparents, who were "so grateful" to everyone in Panama for organising it, Hughes said.

The Aqua Lobo boat was now being sailed to a "safe location" by two friends, who flew to Panama shortly after the attack to support Derryn Culverwell and her children.

It would be kept there until a decision about what to do with it was made, Hughes said.

Three people have now been arrested and charged over Culverwell's killing.

Leandro Herrera and Avelino Arosemena earlier appeared in court over the attack, Reuters reported. They are charged with aggravated homicide, robbery, criminal association and mistreatment of a minor.

A third suspect made a separate court appearance because they are a minor.

Derryn Culverwell had to attend both hearings and was photographed outside court.

She was being supported in Panama by two family members as well as Culverwell's stepson and two friends.

A decision has not been made about when Culverwell's funeral will be held.

The family's boat, Aqua Lobo, is being moved to a safe location. Photos / Facebook

The family were on a dream trip having sold their Marlborough Sounds property and bought a 65-foot launch. They had travelled to Florida to pick it up and were on the journey of a lifetime home when terror struck.

Culverwell had awoken in the early hours after hearing a noise on the boat's roof. He was killed when he went to investigate.

The family had been so meticulous with their preparations but nothing could prepare anyone for this, Hughes said.

It was an unimaginable end to what was supposed to be the adventure of a lifetime.

"Derryn and Alan built a beautiful place down in the Marlborough Sounds in Oyster Bay, and as the children got older they ended up selling that place," Hughes said.

Then the timing had felt right to travel with their kids and the family left New Zealand shortly before Christmas in 2016 after finding a vessel in Florida.

"It was so exciting for them."

In those early days, holing up against the hurricanes seemed like the toughest part of the adventure they would face, Hughes said.