The 5m aluminium boat belonged to another cousin, who was not with them.
But the Christmas holiday fishing trip was to end in tragedy for the men, after they were struck by a rogue wave as they attempted to make their way back across the Manukau Bar about 2pm. The boat flipped, and threw them all into the water.
All five were wearing life-jackets but with no boats close by and authorities unaware of their planned crossing, they were forced to wait in the water until around 4pm when a passing boat, travelling towards Whatipu Beach, came to their aid.
By that time, Mr Woonton and Mr Samuela had died.
Their rescuers pulled out the survivors, and the bodies of their cousins, and took them ashore.
The crew were today praised as heroes by police, who described their efforts as "outstanding".
"Their heroic work should not go unmentioned," Detective Sergeant Alisse Robertson said.
The rescuers took the men to Whatipu Beach, where the Westpac Auckland Rescue Helicopter landed and onboard medics assessed the three survivors.
"They were shattered physically, really exhausted and really cold," Dr Cameron Rosie said.
The trio were taken to hospital, where they were discharged this morning.
The bodies of Mr Woonton and Mr Samuela were taken to Little Huia Bay.
Today, the families of the two men paid tribute to the keen fishermen, describing them both as "very experienced on the water".
Mr Woonton's son Jason praised him as an "awesome husband, dad and grandad".
"He was a welder by trade and a very hard worker. To his friends and family, he was always willing to lend a hand and help out, and his generosity was well known," he said.
"He loved to fish, but not as much as he loved to spend time with his two grandchildren. We loved him very much and we still can't quite believe this has happened."
His dad was a "no fuss" man in life, and "wouldn't want the fuss now", he said.
Mr Woonton's nephew Edward Singapu - who's dad owned the boat the men were fishing in, but was not out with them yesterday - said he was "very knowledgeable" and a "great mentor career-wise".
"He was a kind-hearted, cheerful, very strong/tough bloke," he said. "He was a socialist party guy, who enjoyed all water leisure activities, fishing, diving etc."
The scene of the rescue. Photo / Auckland Rescue Helicopter Trust
On social media, family and friends spoke of their shock at the two deaths, and sent their thoughts and prayers to the two men's immediate family.
Coastguard said conditions in the harbour were "pretty reasonable" yesterday, with a northeast breeze blowing at 10 knots and a swell forecast of about 1m to 1.5m.
"The conditions ... are not excessive, but you don't know what the conditions are until you're actually on the bar," operations manager Ray Burges said.
"I heard other reports that other vessels came through with no issues whatsoever, but I don't know what's happened, anybody can get a freak wave and it's pretty easy to get caught out."
He advised all boaties to inform Coastguard before attempting a bar crossing. If the skipper doesn't radio back within 30 minutes to say they've made it across, then Coastguard will actively attempt to make contact and locate the boat.
Kiwi sailor Graham Dalton, older brother of Team New Zealand boss Grant Dalton, also lent his voice to the safety messages today, describing the deaths as a "predictable tragedy".
"I have lost count of the times coming home in the weekend through the Motihue Channel on the Waitemata with an outgoing tide and stiff southwesterly kicking up a short step sea and observing over-loaded small craft being bailed out to stay afloat," he said. "How they get back to shore is anyone's guess.
"Having raced solo around the world on two occasions in some very difficult conditions, the behaviour on the water leaves me bewildered.
"Perhaps fine tuning regulations would help, but without common sense the tragedies we too often see will continue."
