Saildrone fleet begins five-year loop around Antarctica

The first Saildrone Explorer uncrewed surface vehicle departed Hobart, Tasmania, on Sept. 19, 2026, to begin a five-year trip around Antarctica, though Saildrone’s own account dates the deployment to Sept. 20, 2026.

The voyage is part of COCO2, a five-year research program run by NOAA and Columbia University. COCO2 is short for Constraining Ocean Carbon with Optimized Observing. The program sends Saildrone uncrewed surface vehicles to track how carbon dioxide moves between the ocean and the atmosphere. Its aim is to cut uncertainty in global carbon-sink estimates.

An uncrewed surface vehicle is a boat that sails on the water without people aboard. The Saildrone Explorer is one such craft. It carries no crew and operates on the surface.

NOAA calls the Southern Ocean some of the roughest and most dangerous water on Earth. Harsh conditions have kept research ships away from those waters, particularly in winter. That gap has pushed scientists toward uncrewed systems for observations in the region.

A carbon sink is a natural system that takes in more carbon than it releases. The ocean can serve as one of these sinks. COCO2 seeks to sharpen the global estimate of that ocean carbon sink.

Air-sea carbon exchange describes the movement of carbon dioxide between the ocean and the atmosphere. COCO2 will use Saildrone vehicles to gather data on that process across the Southern Ocean over five years. The data will feed into global carbon-sink estimates.