COURTESY SAILDRONE The SD-3000, Saildrone’s largest model to date, being launched by the Austal USA yard in Mobile, Alabama. The 65′ (20m) aluminum-hull Surveyor model with a fin keel and a patented wingsail was commissioned for the U.S. Navy.
Richard Jenkins, an Englishman trained in mechanical engineering, stepped into the limelight on March 26, 2009, in California’s Mojave Desert by setting a 126.1 mph (203 km/h) land sailing speed record. His landsailer Greenbird featured a sophisticated self-trimming wing sail with a forward-facing rod halfway up and tabs at the trailing edge of a separate fin that protrudes aft of the wing. This setup helped control the wing’s angle of attack with precision (at 126 mph, apparent wind is straight on the nose), so Jenkins could maximize power while expending minimal energy.
In 2014, he developed a 400-sq-ft (37.2m2) variant of this wing for a study to evaluate the feasibility of sail-powered passenger ferries on San Francisco Bay. The wing was mounted on Trillizas, a modified 42′ (12.8m) Cross trimaran operated by Wind + Wing Technologies, a firm that partners with the California Air Resources Board, the Bay Area Air Quality Management District, and the Transportation Sustainability Research Center of UC Berkeley. Used to research fuel savings that could be realized when motor sailing, the boat showed promise, but passenger ferries with wing sails have yet to become a practical reality.
In 2012, Jenkins had founded Saildrone, now based at the old Naval Air Station in Alameda, California. The company designs and builds so-called USV (unmanned/uncrewed sailing vehicles) that feature different renditions of Jenkins’s self-trimming wing sail for propulsion while generating onboard power with solar panels. Saildrones can travel thousands of miles across oceans for survey and surveillance missions and data gathering for defense and research applications, such as environmental observations, including wind speed, wave height, temperature, pressure, and salinity. “It’s a common misconception that saildrones, like aerial drones, have a ‘pilot’ controlling each [USV] from a remote location—i.e., Saildrone HQ in Alameda, California,” the company states on its website. “Saildrones aren’t just unmanned, they’re also autonomous, designed to navigate a set of user-prescribed waypoints, while taking wind and currents into account to stay within a selected navigation corridor, or alternatively, to hold station using precise position controls.” In 2021, the firm announced the close of a $100-millon Series C round, bringing its total funding to $190M and stated that by then, saildrones had sailed a combined distance of more than 500,000 nm and spent more than 15,000 days at sea. They sailed across the Atlantic and the Pacific, circumnavigated Antarctica, and sent video from inside the eye of Hurricane Sam, a Category 4 storm.
Saildrone Goes Big
As the exploits grew more demanding, Saildrone’s design evolved. What started as a small trimaran has morphed into three different sized monohulls with keel ballast—the 7m (23′ ) Explorer, the 10m (33′) Voyager, and the 20m (65′ ) Surveyor, Saildrone’s most substantial craft, with a 13m (44′ ) wing delivering a 6-knot cruising speed, according to published data. It is capable of remaining at sea for three months and can cover up to 2,500 nm powered by its wing sail and auxiliary diesel. The company said that about 30 Voyagers and 15 Explorers are deployed, but more of the latter will be operating in the Northern hem sphere in the summer. Typical applications include hurricane and CO2 flux monitoring, climate science, and fisheries surveys. “With the larger vehicles, we are scaling our services for coastal and open ocean seafloor mapping and maritime security,” a company spokeswoman said. Future growth is expected in seafloor mapping for offshore energy and telecommunications, and maritime defense and security.
COURTESY SAILDRONE The 15-ton Saildrone USV was built to American Bureau of Shipping (ABS) Light Warship code and carries multibeam sonar equipment that can map the seafloor to depths of 36,000′ (11,000m).
Early last March, Saildrone launched the SD-3000, its first production model Surveyor, “designed for long-range, long-endurance ocean mapping and maritime domain awareness,” according to the company press release. Currently, Surveyor USVs are contracted to the U.S. Navy for initial testing and evaluation. In a departure from other Saildrone models built from composite materials, this craft’s hull is aluminum (the sailing wing is carbon and fiberglass composite) by Austal USA in Mobile, Alabama, a big yard with expertise building steel and aluminum military vessels and the capacity to scale production if necessary. Leveraging what Austal calls an “advanced autonomous machinery control system,” the firm also supports unmanned vessel programs.
“We expect the need for ocean observing to continue to grow in size, complexity, and quality,” Jenkins told online technology publication Tech-Crunch. “Aerial, surface, and subsurface technologies all have a role to play in ocean observations,” he said. “Aluminum was chosen for the hull and keel for its robustness, longevity in the ocean environment, cost, and the ability to rapidly mass produce at very large factories like Austal…. We don’t have the same scale of composite production facilities available in the U.S.”
At 65′ LOA with a displacement of 33,000 lbs (14,949 kg), the SD-3000 classifies as a medium USV, built to American Bureau of Shipping (ABS) Light Warship code. The company said the craft is equipped with multibeam sonar equipment that can map the seafloor to depths of 36,000′ (11,000m) and “purpose-built defense and security payloads for accurate, dynamic, and confident decisions and responses to the full spectrum of maritime threats and challenges.” Future missions will focus on surface and undersea intelligence “for a range of high-priority applications, including anti-submarine warfare (ASW).”
Saildrone, 1050 W Tower Ave., Alameda, CA 94501, USA, tel. 415– 670–9700.
Sidebar
COLREGs and SOLAS Concerns
Saildrone pointed out that the ABS issued Approval in Principle (AIP) certificates for the 33’ Voyager and the 65’ Surveyor, stating that it is “an important step to class for Saildrone’s vehicles” and a “formal review process that evaluates the design concept of a new technology, product, or system against ABS rules and applicable regulations as an important first step to full classification.” The firm also says it is “committed to safe operations at sea. All vehicles are equipped with an automatic identification system (AIS) transceiver, navigation lights, high-visibility wing colors, onboard cameras, and/or radar reflector.” However, questions remain about compliance with International Regulations for Preventing Collisions at Sea, 1972 (COLREGs) i.e., Rule 5 (“every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions”) and Regulation 33 of the International Convention for the Safety of Life at Sea (SOLAS) as published by the International Maritime Organization’s (IMO), regarding the response to distress messages (“the master of a ship at sea which is in a position to be able to provide assistance on receiving a signal from any source that persons are in distress at sea, is bound to proceed with all speed to their assistance”). In the past, when uncrewed craft were smaller and lighter, they presumably did not pose a big threat to most oceangoing ships in case of a collision, but that argument is difficult to make for a 65’ 15-ton object like the Saildrone Voyager.
Saildrone Semantics
The company insists on calling their craft unmanned/uncrewed surface vehicles because: “‘Vessel’ is any conveyance that is used to transport people or cargo, neither of which are accomplished by Saildrones,” a spokeswoman explained via e-mail. “Saildrone assets are recognized globally as unmanned/uncrewed surface vehicles, or alternatively, oceanographic science equipment. It is not a vessel and therefore does not need to comply with the same regulations for vessels. Obviously, there are some ongoing global discussions about how this might change and how unmanned assets should comply with Rule 5, and Saildrone is active in those discussions. It’s also why we sought classification for our 10m Voyager and are seeking classification for the new Surveyor.”
There is a precedent of at least one unmanned sailing craft that did not sufficiently comply with COLREGs. In 1999, a college in Furtwangen, Germany, launched RelationShip, a 36’ trimaran based on Dick Newick’s Echo II design. The tri was equipped for an unmanned circumnavigation, but it was not to be. After technical issues and a shortage of funds delayed the project, it petered out in July of 1999 with RelationShip en route to the island of Madeira. The trimaran had to be sailed in and out of ports by regular crew, who got off when open water was reached, continuing their journey on a large catamaran that closely followed RelationShip, because German authorities insisted on the presence of a crewed vessel to ensure human intervention in case of emergency or system failure.
Technology has evolved since then, and uncrewed vehicles have grown in sophistication, size, and capabilities (i.e., autonomous operation as Saildrone claims), but the rules of the road have not changed, so we checked in with the U.S. Coast Guard for an update on the state of affairs: “The Coast Guard’s priority is to effectively manage the risks associated with the increasing use of autonomous and remote-control vessels on U.S. waterways. To evaluate the unique risks associated with autonomous and experimental maritime technology the Coast Guard is working internationally and domestically to develop a suitable governance framework that safely and effectively integrates these technologies into the maritime domain. All vessels, regardless of the number of crewmembers onboard, are required to comply with COLREGs. If commercial vessel owners or operators seek to reduce the number of crew onboard, based upon the use of autonomous technology, they must demonstrate that these technologies are able to comply with COLREGs requirements.” The agency added that it is “actively engaged with IMO on issues related to autonomous vessels and the application of technologies to meet requirements of conventions under IMO’s purview, including COLREGs and SOLAS, to ensure the safe use and implementation of these technologies.”
—D. L.
