Rodney Hide had to be pulled from the water after failing to complete the Auckland harbour swim within the 105-minute time limit.
Hide was picked up by surf life savers 300m from the line in yesterday's race.
"The problem has been that I haven't been able to get to train enough - I've been a bit busy," said Hide after coming ashore.
"I'm a bit disappointed in myself but I'm glad that I was out there having a go."
It was the second time Hide needed assistance. The first was in 2006 when he said the current was too strong.
The race was won by Dunedin's Bryn Murphy ahead of Olympic pool swimmer Moss Burmester.
New Plymouth's Charlotte Webby won the women's race.
Another top athlete to take part was double Olympic gold medallist Danyon Loader, competing for the first time in 10 years.