International marine scientists studying how global warming is changing the deep ocean plan to trial new versions of remote measuring devices off the coast of New Zealand.
Existing versions of the Argo floats are capable of monitoring the top 2km of water, while the new models will measure temperature and salinity 6km deep.
Australian scientists say the deeper water is a living history of human impacts on the atmosphere.
Susan Wijffels from the Commonwealth Scientific and Industrial Research Organisation in Hobart told the ABC she will trial prototypes by dropping them off the side of a New Zealand ship this winter.
"We hope it will go out of Wellington and we will go to a nice flat place in the south-west Pacific that's quite deep, but very flat, and what we can do there is test the sensors against the ship based system, which is very, very accurate.
"And we also hope to deploy a whole bunch of deep floats there, four or five - more if we can get them, so we can inter-compare how the float born sensors compared with the very accurate sensors on the ship."
Dr Wijffels hopes to soon have hundreds of the deep sea floats active.