The U.S. Navy has had considerable success in developing and testing large ocean-going USVs (unmanned surface vessel). This is the Ghost Fleet Overlord program that is developing Class 4 USVs (those over 50 meters/160 feet long). The navy has built two development Ghost Fleet vessels (Nomad and Ranger) for testing, each displacing about 2,000 tons. Both have made autonomous voyages, travelling about 8,000 kilometers from the American Gulf coast to the West coast, including transit through the Panama Canal. These voyages had the ships in autonomous mode 98 percent of the time. A small crew was on board in case of problems, but there were none. Each vessel picked up a pilot for going through the Panama Canal. The navy wants to buy ten of these Ghost Ships for operational use, mainly in the Pacific where China has a growing number of anti-ship missiles, including a ballistic missile, for use against American ships. The autonomous ships will be armed with a dozen or more VLS cells carrying anti-ship and land-attack and anti-aircraft missiles as well as RWS (remote weapons stations) armed with machine-guns or autocannon for defense. The main function of the Ghost Ships would be ELINT (Electronic Intelligence), ASW (Anti-Submarine Warfare) and similar support functions. Encrypted satellite communications would handle sending data and receiving commands from manned ships or land bases. Sensors include the usual array of vidcams, radar and acoustic sensors to help with navigation and security. On the open ocean these ships could be boarded by hostile forces seeking to take over the USV or just plunder it (as in pirates) of anything valuable and portable. There will probably be a landing pad for manned or unmanned helicopters. The unmanned aircraft would assist with the mission while manned helicopters could land to deal with any malfunctions if a ship was not close enough to take care of this.
These larger USVs take advantage of technology already used on smaller coastal and harbor USVs as well as tech already in use by commercial firms for large ferries and cargo vessels. Commercial ships have pioneered the use of automation on large ocean-going container and tanker ships. That means a crew of about 30 for ships as large as an aircraft carrier but only carrying cargo. Most of the time these ships navigate autonomously and the crews are for maintenance, including quickly dealing with equipment problems. Commercial ships, like commercial airliners and transports are more heavily used than military ships and aircraft. Time is money for the heavily used commercial ships and aircraft and both spend most of their time in the air or at sea.
Automation, including navigation and open-seas movement is already largely automated and human intervention is only needed to complex maneuvers, like getting into or out of a crowded harbor or getting through canals (like Panama or Suez), For the canal transits the canal operators provide pilots, as do many harbors that handle very large cargo or tanker ships.
The Ghost Fleet Overland program builds on decades of development and use of smaller military USVs, including autonomous ocean-going UUVs (Unmanned Underwater vessel) the size of a torpedo and able to stay at sea up to year at a time. Originally developed for scientific research, these autonomous USVs were seen by the navy as an ideal tool for monitoring undersea conditions constantly and inexpensively. This data is important to detecting submarines.
These smaller USVs and UUVs have gone through several generations of development and use. For example, in 2019 an Israeli firm introduced its new Seagull coastal USV. This USV is equipped with a HELRAS (Helicopter Long-Range Active Sonar) active low-frequency dipping sonar that is normally used by a helicopter to pinpoint the location of a submarine before launching a lightweight torpedo. Seagull can carry and launch one of those torpedoes after HELRAS has located a target, usually a naval mine sitting on the ocean bottom in coastal waters.
While Seagull development concentrated on mine detection and destruction, the remotely controlled boat can carry 2.5 tons of specialized equipment and has been tested with many systems, usually in the presence of officers from various navies as well as representatives from the European and American companies that build the mine-clearing, anti-submarine, EW (Electronic Warfare) and anti-swimmer (frogman) systems Seagull users can purchase and use. Improved relations between Israel and the Persian Gulf Arab states make those nations potential customers. Iran is a mutual enemy and Iran poses several naval threats to its Arab neighbors. Seagull offers a cost-effective way to deal with numerous Iranian threats like small submarines, naval mines and armed speedboats. Standard equipment on Seagull enables it to operate safely in areas containing other ships, both large and small. Seagull navigation sensors can automatically detect and avoid other ships as well as underwater obstacles.
In mid-2017 Seagull demonstrated its ability to perform MCM (mine countermeasures) missions (finding and destroying bottom mines) off the Belgium coast in rough weather. Seagull was designed to operate in Sea State 5 (six-meter waves and 38 kilometer an hour winds) conditions and survive Sea State 7 (nine-meter waves and 59 kilometers an hour winds).
Each Seagull system consists of two Seagulls and a base station. The Seagull is based on a small manned boat and retains the wheelhouse. From a distance, it looks like a manned boat. In fact, Seagull is either operating autonomously or remotely by human operators using base station control equipment that can be up to a hundred kilometers away on land or a manned ship. The base station crew includes the three people needed to operate Seagull and its equipment. For MCM work, one Seagull carries several types of sensors (onboard, towed and autonomous sonars) while the other Seagull carries a minisub for getting a closer look at bottom mines. Small wire-guided torpedoes are used for destroying subs or bottom mines.
A Seagull USV is 12 meters (39 feet) long, has a top speed of 57 kilometers an hour and can stay at sea for up to 100 hours (four days) at a time. Each Seagull system will cost from $12 million to $30 million depending on installed equipment. Seagull can do the work of a manned MCM (mine countermeasures) ship costing three times as much or, when it comes to ASW (anti-submarine warfare) operations, a frigate or corvette costing ten times as much. Seagull is a lot cheaper to maintain and operate and puts far fewer personnel at risk.
Seagull also has an RWS (Remote Weapons Station) armed with a 12.7mm machine-gun. When a threat is detected, an operator can control the machine-gun or if Seagull communications are jammed the USV can be programmed to fire on certain types of targets autonomously. This makes Seagull an effective way to guard ports and offshore facilities. The Israeli Navy plans to use them to guard Israeli offshore natural gas wells in addition to the pipeline carrying the gas to shore.
Seagull is not a radical new concept but rather the result of decades of unmanned aerial, land and naval vehicle development. The Israelis have been in the lead in most categories. The American Predator UAV was based on Israeli designs. Israeli firms continue the development of these autonomous systems. For example, in 2013 an Israeli firm presented a larger (11 meter/34 foot) version of their original nine-meter Protector USV. This one was armed with a water cannon and Spike missiles. The 2013 model was more stable in rough seas and can stay out for over 12 hours at a time.
The original Israeli USV was the 2005 version of the Protector, a four-ton, 9 meter (30 foot) long speedboat that could move at up to 72 kilometers an hour and was armed with an RWS 12.7mm machine-gun using night vision and a laser rangefinder. Both versions of Protector were equipped with radar, GPS, and vidcams, as well as a public address system, to give orders to boats that should not be there. All these features were carried over to the Seagull.
Protector has been used since 2005 in places like the Israeli coast, the Persian Gulf, and Singapore for port and coast patrol. Protector can be controlled from an operator ashore or in a nearby ship, usually out to the horizon or at least 10-20 kilometers distant. The original Protector could stay out eight hours at a time. The one big shortcoming was Protector being built for speed, not rough seas. So when the weather turns bad, and the waves get higher, Protector has to be brought in. Protector is used to patrol the Gaza coast and the waters around the Lebanese border. These USVs were also used off Gaza during the several wars with Hamas in Gaza.
Seagull development was driven in part by the need to guard the new Israeli offshore natural gas fields and the pipelines moving the gas to shore. Most of these natural gas operations are near the maritime border with Lebanon. Seagull is being offered to trusted allies who need a less expensive way to deal with MCM and ASW operations. NATO nations, especially those with coasts bordering the North Sea and Baltic Sea are particularly concerned about MCM and ASW capabilities now that Russia has become more aggressive.
The United States has also developed similar small USV systems but so far Israel is in the lead and the Americans have cooperation agreements with Israel to share tech, some of which is jointly developed.