Kayaking between Auckland and Waiheke Island allowed Rotorua's Henk Greupink time to reflect on events since last Friday's terror attack in Christchurch.
The swim coach was supporting friend and master's swimmer David Blackmore who, with two others, swam the distance to raise funds for Auckland's rescue helicopter.
"When you're out on the water for that long you start thinking," Greupink said.
"I was trying to come up with something personal to support the people of Christchurch but also something that would allow people taking part to grieve, or get rid of anger."
He came up with the 50x50 at 50. That's 50 lengths of 50 metres at 50 second intervals.