Grogan said Taniwha would also allow Ngai Te Rangi to access the wider harbour in a range of conditions, and was an opportunity to enhance their kaitiaki (guardianship) responsibilities.
The iwi could be contracted to work collaboratively with the council on tasks such as supporting the monitoring of the navigation bylaw, supporting harbour environmental monitoring and oil spill responses, and using Taniwha for litter clean-ups in hard to reach places around the harbour.
Grogan said the work would be undertaken at a rate to offset the ''reasonable'' cost of the council leasing Taniwha to Ngai Te Rangi.
Taniwha was valued at $150,000 which meant the council was foregoing interest of $7500 a year on the vessel. At a standard contract rate of $700 a day for boat and crew, this equated to 100 hours of work a year.
All maintenance and operating costs would be met by the iwi, with the qualified crew supplied by iwi, he said.
Ngai Te Rangi chief executive Paora Stanley said the iwi was interested in playing a stronger role in environmental protection of the harbour.
He also saw value in Taniwha operating as a search and rescue vessel using specially trained iwi members. One idea was to design a detachable ambulance module that could be fitted to the boat for emergencies.
Stanley said Maori were over-represented in drowning statistics, so it could be used for water safety and boat safety courses.
Ngai Te Rangi chairman Charlie Tawhiao said Taniwha would become a base for research to support the health and wellbeing of the harbour.
''It is another opportunity for the council to expand its own influence on what happens in the harbour.''
Other roles for Taniwha included helping iwi members gain their skipper's certificates and to transport people out to where courses were being run at Tuhua (Mayor Island).
Taniwha
- Built 2009
- Length 9m
- Powered by twin Yamaha 225hp outboards