For the first time in history, an unmanned wave glider completed a 9,000 nautical mile (16,668 kilometers) scientific journey across the Pacific Ocean. The trip, made by a wave glider called “Papa Mau”, set a new world record for the longest distance traveled by an autonomous vehicle. The honor is made even sweeter by the fact that the glider is the first marine robot to use wave energy to propel itself forward.
Why did this robot boat spend a year slowly chugging across the Pacific, you might ask? The reason becomes clearer when you know who the glider belongs to. Last November, a company called Liquid Robotics released Papa Mau and three identical wave gliders off the coast of San Francisco in an attempt to collect data and prove the potential of their wave-powered technology. Over a year later, and Papa Mau is the first to reach Australia, all the while transmitting unprecedented amounts of high-resolution ocean data never before available over this vast distance.
So how was this possible without any fuel or motor? As explained on the company’s website, “Wave motion is greatest at the water’s surface, decreasing rapidly with increasing depth. The Wave Glider’s unique two-part (float above the surface and tethered sub below) exploits this difference in motion to provide forward thrust.” When a wave lifts the float up, the sub comes along, but quickly sinks again. This sinking motion soon pulls the Float forward and off the wave. This process is repeated again and again as long as there is wave motion on the surface, even the smallest amount.
During Papa Mau’s year-long journey, he weathered gale force storms, fended off sharks, skirted around the Great Barrier Reef, and finally battled and surfed the East Australian Current (EAC). He traveled through and measured over 1200 miles of a chlorophyll bloom along the Equatorial Pacific. These blooms indicate proliferation of phytoplankton that is fundamental to ocean life and climate regulation. While typically monitored through satellite imagery direct validation of chlorophyll blooms at this resolution provides a groundbreaking link between scientific modeling and in-situ measurement of the Pacific Ocean.
All data gathered by the four wave gliders is available for free to anyone who registers on the Liquid Robotics website.