Mr Rolton, Mr Otto and Kevin Hicks were travelling to Nelson for a fishing charter trip when the friends decided to take a break at the scenic waterfall on the Maruia River south of Murchison.
Police said Mr Otto climbed over the barrier fence and paddled in one of the streams above the rapids before being sucked down a chute and over the falls.
Mr Rolton leapt in to try to rescue him while Mr Hicks alerted travellers in the car park below the falls to help in the rescue.
Both men were trapped in the two huge whirlpools on either side of the falls. Mr Otto was eventually pulled from the water and flown to Nelson Hospital with suspected spinal injuries by the Nelson-Marlborough Rescue Helicopter.
Mr Rolton was seen floating face down in the water before disappearing. His body was recovered by the police dive squad on Monday.
Mr Rolton's nephew, Brett Olsen, said his heroic action was typical of his uncle.
"Darryl being Darryl would never hesitate to help a friend in trouble," Mr Olsen said.
"We've been in situations together and he'd never back down in a charismatic sort of way. If you needed a man at your back, that was Darryl. He'd never leave a man in danger."
Mr Olsen said Mr Rolton's family was proud of the rescue attempt that cost his life.
"We're definitely very proud of what he tried to do," he said.
"You only get one chance in life and he took it with both hands. He never hesitated to do the right thing."
Mr Olsen and Mr Rolton grew up together in Dunedin.
"I regarded him as a brother, rather than an uncle," he said.
"He was a very colourful sort of chap ... mischievous in more ways than one. He had a heart of gold and would do anything for anyone.
"You just had to take him with a grain of salt. If you met him, you'd either love him or hate him."
Mr Olsen said Mr Rolton was a "dedicated painter and decorator" who had worked in the trade "on and off" for about 28 years. He was a site foreman for Garden City Plasterers and Painters Ltd.
"They'd just got a good contract and he was looking forward to the work," he said.
Mr Olsen said Mr Rolton had been married, but his former wife had moved to the United States. He had been in a new relationship for about a year.
Mr Olsen said the three friends were heading to Nelson where they planned to charter a boat for a fishing trip.
"They were going up to do some fishing and to have a good time. Obviously they stopped at Murchison to relax."
Police said alcohol might have been a factor in the tragedy, but Mr Olsen said that hadn't been confirmed.
"Darryl liked a few beers, but who doesn't?"
Mr Olsen said his uncle could "put his hand to anything".
"He loved his motorbikes, his tattoos, his fishing and his friends.
"He had a great work ethic. You couldn't ask for a better painter and paperhanger."
Mr Rolton will be farewelled at a funeral service at the Canterbury Crematorium in Linwood Ave on Friday.
Sergeant Steve Savage, of Nelson police, said he was aware of at least five deaths at the deceptively dangerous Maruia Falls. People continued to ignore safety barriers to climb onto rocks above the falls.
"A Belgian tourist had a close call last Wednesday when he was sucked down a similar chute while taking photographs," Mr Savage said.
"It's a lovely spot to go and watch, but it's not a place to get too close to."
Mr Savage praised Mr Rolton's heroic efforts.
"His intentions were really good to hop in and try to help a mate. It's really unfortunate for all involved."
