New ocean-sensing drones are being built to withstand the deepest depths. More than 70 percent of Earth is covered by ocean, but the vast majority remains unexplored. Today, the vast majority of ocean data comes from the Argo Program, an international collaboration launched in 1999 deploying 4,000 floats worldwide.

These typically descend between 2,000 and 4,000 meters, yet 10 percent of ocean warming occurs below these depths, marking a major data gap. This year, Ifremer — the French state ocean agency — reported its two Deep-6000 prototypes completed five dives of 6,000 meters between January 11 and February 2, making France the third country after China and the United States to develop such technology. By 2028, 30 more deep-sea floats will join the existing Argo-led international fleet of 4,000 devices, allowing researchers to explore more than 98 percent of ocean volume.

The US currently operates more than 100 deep-sea floats and China operates more than thirty. To accommodate pressure, Ifremer constructed hulls with composite materials other than pure titanium. At 88 pounds, the devices weigh approximately twice as much as a typical Argo float.

Float missions run on ten-day cycles: the float descends to a drift depth for nine days, then profiles for three hours before ascending and sending data to a satellite via surface transmission. This process repeats until battery depletion, usually around 150 cycles over three to five years. The floats collect data on water salinity, temperature, oxygen, and pressure to help scientists understand ocean behavior amid climate change.

Virginie Thierry, a physical oceanographer at Ifremer, stated the new Deep-6000 floats will allow tracking ocean warming through abyssal depths and obtaining information on deep ocean circulation, which contributes to climate signal storage.