On 17 November 2011 four Wave Gliders left San Francisco for a 60,000 kilometer journey across the Pacific Ocean. The self-propelled robots, built by Liquid Robotics, will travel together to Hawaii, then split into pairs, one pair heading to Japan, the other to Australia. Waves will power their propulsion systems and the sun will power the sensors that will be measuring things like water salinity, temperature, clarity, and oxygen content; collecting weather data, and gathering information on wave features and currents.