Organiser Tim Guthrie said a decision was made to cancel the first leg - a circuit race starting on the Clutha River at Balclutha - as winds started gusting up to 55kmh.
High winds had the potential to launch the boats into the air.
"The boats get lift anyway, so the last thing you want is wind around them. They start turning into wings," Guthrie said.
The winds died down after lunch and the second leg, from Clydevale to Roxburgh, was held without a hitch.
Mr Guthrie said there were various classes in the competition, based on engine capacity ranging from small-block V8 engines to engines of more than 7700cc and boats powered by gas turbine helicopter engines which could produce up to 1400hp.
They were able to reach speeds about 230kmh, he said.
There are 24 competitors - most from the South Island - including one from Canada and one from the United States.
John Derry, of Blenheim and Regan Williamson, of Queenstown, are tied after the first day of racing.
The three-day event continues today on the Dart River and tomorrow on the Matukituki River and Lake Wanaka.
