One of oceanography’s greatest challenges is providing researchers with the access they need to the open seas. Research vessel cruises are essential, but for a given group usually infrequent, with each providing only a small window of data. Long-term monitoring is often critical but difficult to accomplish at the surface due to the cost, range, and other limitations of existing autonomous and moored vehicles and buoys. But, many of those limitations might be overcome by using a new type of drone developed by the Saildrone company in collaboration with the Marine Science and Technology Foundation. This vehicle could redefine ocean monitoring by going further, faster, and more cost effectively than any other self-powered autonomous surface vehicles.
The Saildrone is a 19-feet-long by 19-feet-high autonomous sailing vessel that can operate independently at sea for months at a time even in the worst weather conditions. It can reach speeds over 16 miles per hour, cruising at an average speed of five. Wind and solar energy harnessed by a few panels on the deck provide all the power needed for long-term deployment.
The vessel uses solid wing technology that Saildrone co-founder and engineer Richard Jenkins spent ten years developing for Greenbird. This solid-winged racer grabbed the world speed record for a wind-powered vehicle on land when it hit 126.2 miles per hour on a Nevada dry lake in 2009 with Jenkins at the wheel.
Beyond longevity and speed, Saildrone’s most vital asset is a 220-pound payload—more than enough to accommodate a wide range of oceanographic sensors, ranging from standard equipment such as temperature and oxygen probes, to pH meters and other more specialized systems. Drawing on the underwater robotics expertise of Saildrone’s CTO Dylan Owens, all electronics are encased in pressure-rated submersible housings that offer extreme longevity.
The Saildrone can follow a pre-programmed track or operators can use a web app to control the platform via the vehicle’s Iridium satellite communications system. A tail plane orients the sail to the best angle depending on local wind conditions. Operators can adjust a Saildrone’s course around major weather fronts. However, even if caught in high winds, its high strength carbon fiber construction allows it to withstand fierce ocean conditions. Shore personnel can also send course changes to maximize research benefits. For instance, if data sent back via satellite reveal an interesting trend, a Saildrone might be commanded to gather additional data in a given area.
A prototype Saildrone has just completed a 2100-nautical-mile crossing between San Francisco and Honolulu—by far the longest and fastest unassisted voyage ever made by an autonomous surface vessel. Only one other autonomous surface vehicle, Liquid Robotics Wave Glider, has accomplished such a crossing before, and it took several months. Saildrone completed the same feat in just 34 Days.
During the crossing the vehicle has proven itself capable of withstanding sea and wind conditions equivalent to a tropical storm, and has clocked speeds of over 16 miles per hour. “Those first few days of the passage were incredible,” says Jenkins, “clocking 130 miles per day for the fist 5 days." By comparison, research vessels typically cruise at about 10-12 miles per hour and cost tens of thousands of dollars per day to operate, compared to pennies for a Saildrone.
The Saildrone team has already made major progress toward putting vehicles, now under construction, to use through three key programs that will highlight different aspects of their expansive potential:
1) The second Saildrone, which is nearing completion, will enable a unique shark-tracking project in collaboration with Barbara Block, a renowned marine biologist at Stanford University’s Hopkins Marine Laboratory. For the first time, Saildrone speed will offer researchers such as Block the ability to virtually follow fast swimmers like sharks, whales, and tuna for months on end. In the process, the drone can capture critical data on temperature and other factors to give context to an animal's movements that should reveal some of the factors that drive migration patterns and other behaviors.
2) One of six additional Saildrones under construction will enable a previously impossible study of ocean acidification in collaboration with the National Oceanic and Atmospheric Administration and the California Acidification Network (C-Can).
While recognized as one of the most significant threats to ocean health, there are many open questions about how ocean acidification is proceeding and with what impacts. One challenge is that many of the changes tied to acidification occur in waters relatively close to shore. Ships can’t operate effectively in this zone, and seaweed and other obstacles stymie existing drifting buoys and gliders. In contrast, a Saildrone has enough power and speed to handle nearshore currents and waves, its raked back and slippery keel avoids kelp and other entanglements, and it can operate in just six feet of water. “A Saildrone can tack up and down the coast all day long in shallow water with very little risk, so it can record the areas where all the action and biology are happening,” says Jenkins.
For this work Jenkins and his collaborators will fit a Saildrone with a range of pH and carbon sensors. But, in the future, they hope to fit saildrones with a new range of devices, evolved in response to the Ocean X-Prize challenge sponsored by Wendy Schmidt, co-founder of MSTF’s sister organization the Schmidt Ocean Institute. One million dollars in prizes will go to the teams that produce the most accurate sensors, and another million will go to teams that produce the most affordable sensors.
3) Working again with NOAA, the Saildrone team aims to demonstrate that it’s vessels offer an affordable alternative to the current system of anchored buoys used to monitor weather and ocean conditions offshore. The agency is constantly dealing with the loss of data from buoys that break their moorings, or become otherwise incapacitated. In more difficult areas, at times only one out of three buoys might be properly functioning. The great expense of maintenance, recovery, and deployment severely limit the extent of networks.
Saildrones can be fitted with the same sensors as those used on current buoys and dispatched for six-month stints as buoy replacements. A Saildrone could return to shore every six months with a replacement sent to take its place, thus offering numerous cost savings over conventional buoys that could enable dramatically better and cheaper monitoring networks.
“The scientists tell us Saildrone is a potential game changer for ocean science,” says Jenkins, “The only doubters were those who didn’t believe it could survive for long durations at sea, but with a successful Pacific crossing to Hawaii and 5000 ocean miles under the Saildrone’s belt, we’ve proved that now.”