If you happen To cross the San Francisco Bay or Golden Gate bridges this week, look for a massive surfboard with a red sail on top slowly cruising the water. Don’t flinch if you can’t see anyone on board. It is actually an autonomous research vessel known as the Ballast Heaver Saildrone and it is directed away from the shore.
The 72-foot-long ship launches into the bay this week from its dock at a former naval base in Alameda, California. It’s designed to spend months at sea mapping the seabed with powerful sonar, while simultaneously scanning the ocean surface for genetic material to identify fish and other marine organisms swimming below.
The carbon fiber composite vessel and stainless steel hull will sail on its own, following a pre-programmed route to collect and transmit oceanographic data to Saildrone headquarters via a satellite link. The data will then be made available to government and academic scientists studying the ocean. Over time, say its designers, they hope that Solar-powered Surveyor could replace existing ocean research vessels that are much more expensive to operate and leave a significant carbon footprint.
“Our goal is to understand our planet,” says Richard Jenkins, founder and CEO of Saildrone, the California-based company that has spent the past 15 years designing previous versions of ships about a third the size of Surveyor. “There are many reasons why you need information on the seabed, from knowing where to place telecommunications and transoceanic cables, to safe navigation or looking for submerged seismic faults that cause tsunamis.”
Another use is the construction of new energy infrastructure: Wind farm developers must know the underlying geological conditions before submerging the structures into the seabed. “There are also economic needs as we move to renewables. Wind farms require substantial mapping to build wind turbines, ”Jenkins explains.
After completing sea trials over the next few weeks, the surveyor’s first assignment will be to navigate from San Francisco to Hawaii. Along the way, he will map uncharted regions near a series of seamounts where fish and other marine life congregate. The trip to Hawaii will also serve as a shakedown cruise for its new set of sensors, which includes two multibeam sonars that emit multiple sound waves from a device below the ship. These sound waves are then reflected both off the ocean floor and off items in the water column, such as bubbles or fish. As the sound waves bounce back to the vessel, the multibeam echosounder receives the waves, interprets the data, and creates visualizations of all three-dimensional space beneath the vessel. The Surveyor’s multibeam sonar can reach a depth of 7,000 meters (about 23,000 feet), which would cover the depth of most of the world’s oceans. There is also a device called an Acoustic Doppler Current Profiler that can detect the speed and direction of water currents up to 1,000 meters (3,280 feet).
Scientists have been diving to the bottom of the sea in manned submersibles for decades, ships like the newly retooled Alvin which can carry three people up to 6500 meters. While crewed vehicles allow researchers to get close to hydrothermal vents, eruption of underwater volcanoes or unusual deep-water marine habitats, they can only go down for a few hours and are much more expensive to operate than a drone like Saildrone Surveyor.
Oceanographers want to understand the circulation of ocean currents to get a better idea of how heat and carbon are absorbed by the atmosphere and then distributed in the ocean, Jenkins says. Over 90% of the heat trapped by carbon emissions is absorbed by the oceans, making their heat an undeniable signal that the crisis is accelerating. Researchers want to improve their estimates of the overall heat and carbon budget – where heat and carbon are both stored and released – to better measure how quickly the atmosphere and ocean are changing and what effects might be felt in the future. Saildrone Surveyor will collect current and temperature data with its onboard sensors.