New York Times: No Sailors Needed: Robot Sailboats [Saildrone] Scour the Oceans for Data, September 4, 2016
The Saildrone autonomous sailboats look a little like shrunken America’s Cup racing yachts — small trimarans with hard, carbon-fiber sails.
The Saildrone’s carbon fiber sail acts like an aircraft wing. When air passes over it, thrust is created. The sail is stabilized by a counterweight that is placed in front of it and a tab trailing behind it that can automatically make small corrections to make sure it maintains an efficient angle to the wind. Underneath the boat are both a rudder to aid in steering and a keel, which will right the boat if it is knocked over.
The big difference, of course, is that there are no sailors on board. The boats are controlled through communications satellites from the operations center here as they collect oceanographic data and monitor fish stocks and the environment.