The device, costing upwards of $60,000, would provide a constant stream of data about such things as the lake's temperature, clarity, oxygen level, acidity and algal content.
Guardians chairwoman Helen Tait says the buoy idea has been "in limbo" for the past 18 months, but the guardians will take another look at how to pay for it after a workshop is held on the state of the lake later this year.
She was "extremely disappointed" an application for funding to the Central Lakes Trust some time ago was turned down.
"It seemed to us it was absolutely, exactly, up their alley."
The buoys were developed at the University of Waikato to monitor the health of lakes and have been deployed on six lakes in the North Island in the past five years.
Two buoys have also gone overseas.
University of Otago limnologist [lake researcher] Dr Marc Schallenberg is one of those backing the buoy idea for Lake Wanaka.
"They're pretty much the way to go in the future for monitoring big lakes."
The buoys have sensors stretching from the bright orange buoy on the surface all the way down the mooring line to the lake bed below.
The data can be transmitted to a land-based computer.
Dr Schallenberg stressed the importance of "the quality of the data you get from a buoy that's out there monitoring every 15 minutes or every hour".
Currently monitoring is done by the Otago Regional Council, which takes monthly water samples.
Dr Schallenberg believed Lake Wanaka was undergoing rapid change, evidenced by the rise of an algae known as "lake snow".
And he believed a monitoring buoy would help scientists understand what was driving the algae increase.
In the North Island, the buoys are funded mainly by regional councils and Dr Schallenberg believed the Otago Regional Council should be following suit.
However, Mrs Tait said the guardians preferred to find funding from sources other than the regional council so the device became a permanent fixture in Lake Wanaka.
"What we wouldn't want is for the regional council to drop a deep water buoy, take a reading and say 'absolutely clear. No problem at all. We'll move the buoy somewhere else'."
Mrs Tait considered it was important to monitor long-term trends and allow comparisons with deep-water lakes elsewhere in the world.
"It's having that longitudinal data you can compare year on year and lake against lake."
