Jetski owners in Bay of Plenty will join those in Waikato, Auckland and Northland in needing to register their vessels.
The change was introduced as part of the new Navigation Safety Bylaw for identification and safety reasons, says Bay of Plenty Harbourmaster Peter Buell.
"Jetskis are incredibly powerful, fast and manoeuvrable machines," he said.
"For the most part, users play safe and follow the rules, but we do get a lot of speed-related complaints about them. Registration will help us to locate the owners or users of machines seen breaking the rules."
Having a jetski registered is helpful if it is stolen or one is found unattended, Mr Buell said.
Registration can be done online and costs $73.50, which is valid for the lifetime of the jetski.