The inaugural bathtub race off Te Tii Beach in Paihia proved too tough for locals as Whitianga's John Booker made a clean sweep of his heat and the final race.
First prize was a trip to the Nanaimo Marine Festival in British Columbia, Canada, in July.
The experienced "tubber" said he and George Oates from Te Puke, who was second overall, had agreed on a deal before the Paihia event.
"We said to each other that whoever wins the race will take the other one and our wives to the world event."
They will fly to Canada courtesy of Air New Zealand Grabaseat to the home of the original international Bathtub Classic race which started in 1967 to mark Canada's centennial year. The international event now attracts 200 competitors and although Mr Booker was hoping to take his home-built bathtub with him, he was unsure if he'd be able to compete there.
Sixteen competitors in 12 boats entered the Far North's first event, which was held in choppy conditions.
Best of the local competitors were Pete Seymour and Graeme Rigden, both entered by Ashby's Boatyard. Winner of the ladies' event was Helen Horricks, of Paihia.
Lewis Kidman, of Russell won the Seagull event for teenagers.
Organisers of the first bathtub event in the Bay of Islands are hoping to introduce a national series of bathtub races around New Zealand with the final being run in Paihia next year.