Polar orbiting satellites, equipped with random access data collection and position fixing systems, have made practicable long-term remote oceanographic and meteorological observations by means of instrumented drifting buoys fitted with u.h.f. telemetry transmitters. The paper discusses the performance of nine buoys, deployed by the Institute of Oceanographic Sciences as part of the FGGE Southern Hemisphere Drifting Buoy Network, and presents a small fraction of the considerable data set acquired to date. The requirements for further development of certain sensors and components of buoy hardware are brought out as a result of the experience with these buoys.