A custom lightweight boat with a bow-mounted electric motor that steers using GPS technology is the latest tool helping to protect Northland lakes.

Dubbed "Mudfish", the 3m carbon-reinforced fibreglass vessel weighs less than 50kg and was built for the Northland Regional Council by Paihia-based Offshore Cruising Tenders.

Specialised features include the bow-mounted electric motor.

Mudfish is used by council staff to monitor the health of Northland's many lakes, including its rare dune lakes.


Environmental monitoring officer Andrew Macdonald said the remote-controlled motor could accurately hold the Mudfish at pre-determined locations using GPS while staff do their sampling.

The tiny $8000-plus vessel was commissioned 18 months ago.

"The new boat is carried on a special roof rack on a council 4WD and is much easier to retrieve and recover, especially in rough and steep terrain or in remote areas without easy access to the water," Mr Macdonald said.

A specialised loading system lowers and raises the boat using a standard electric drill to power it and permanently attached, fold-away wheels at the boat's rear make it easier to launch and retrieve. The lack of a trailer, which can snag and spread aquatic weeds and the seeds and eggs of pest species, makes for fewer biosecurity risks.

"Another bonus of not having a trailer is that we are far less likely to get stuck," Mr Macdonald said.

Mudfish carries a range of equipment including chart plotting, side scan sonar and water quality monitoring gear.

"Although it's only 3m long, it offers a lot of internal space and it's virtually unsinkable."