The winner of the race will receive the coveted title of New Zealand's best bathtubber and be flown by Air New Zealand to Canada to watch the World Championships in Nanaimo next year.
"Bathtub racing has become a highly popular sport worldwide and is a fun, inventive way of getting people motivated to get out on the water," Brown said.
"This event combines Kiwis' love of the water with our inventive bent so is sure to attract many enthusiast competitors."
Two motorised bathtubs whizzed around Auckland Harbour last week, hitting speeds of up to 35km/h. The culprits were tubbing enthusiasts Graeme Rigden and Peter Seymour in their custom-built crafts.
Entry is now open to anyone over 16 years, with separate classes for men, women and teens.
For more information, visit http://www.bayofislandsbathtubbing.com.