Nature: As of 6 June, the seven underwater instrument arrays that make up the Ocean Observatories Initiative (OOI) are up and running. Nearly 10 years in the making, the NSF-supported project aims to stream information gathered by more than 900 sensors on the ocean’s physical, chemical, geological, and biological properties and processes. About 85% of OOI data are available in real time on the project’s website, and more will be added each week. The array off the US East Coast has already measured the air–sea fluxes caused by a hurricane, and the West Coast array has studied a warm patch of water influencing weather patterns in California. Proposed budget cuts, however, threaten to affect the servicing of the instrument arrays, which have yet to be properly tested. At least a year’s worth of data will be needed to assess their worth and usefulness to the scientific community.