Yesterday's racing was for single person waka ama canoes and today and tomorrow features racing for those aged 19 to 70.
Waka ama sees six paddlers working together as a team over distances from 500m to 1500m and in marathons of 30 to 75km. The ama, or outrigger, on the left hand side balances the waka, or canoe.
Outrigger canoes have been used by every Polynesian culture for thousands of years as a means of transport and a way of life.
Building materials have changed but the paddling technique remains the same.
The week's distances are sprints with the shortest at 250m and the longest 1500m.
There are straight races and races where the crews have to negotiate five hairpin turns, adding excitement for spectators.
The corporate waka ama challenge final tomorrow features the top New Zealand Post corporate teams from Auckland, Wellington and Christchurch keen to be the company's best team.
Alongside the event, there are water safety messages and swimming instruction in a portable swimming pool in the Lake Karapiro complex car park.
The event offers the opportunity for waka ama paddlers to learn more about taking better care of themselves and their mates in oceans, rivers and waterways.
Water Safety New Zealand is leading the instruction. Its chief executive Matt Claridge says Maori and Pacific Island groups are over represented in drowning statistics and the nationals are the ideal opportunity to deliver vital water safety messages and education to participants and their supporters.
Entry is free for spectators.