In April, two semiautonomous drones, developed by Saildrone, a marine tech startup based in Alameda, California, in close collaboration with the National Oceanic and Atmospheric Administration in Washington, D.C., are set to return from an 8-month tour of the Pacific Ocean. This the first scientific test for the drones, which are powered only by the wind and sun, in the Pacific Ocean. The voyage is an important step in showing that such drones, carrying 15 different sensors, could help replace an aging and expensive array of buoys that are the main way scientists sniff out signs of climate-disrupting El Niño events. If successful, scientists envision fleets of similar drones spreading across the ocean, inviting thoughts of what it could be like to do oceanography without a ship.