Israel has developed a larger (11 meter/34 foot) version of their original nine meter Protector USV (unmanned surface vessel). This new one is armed with a water cannon and Spike missiles. The new Protector is more stable in rough seas and can stay out for over 12 hours at a time.
The original Protector USV is a four ton, 9 meter (30 foot) long speedboat that can move at up to 72 kilometers an hour and is armed with a remote control 12.7mm machine-gun (using night vision and a laser rangefinder). Both versions of Protector are equipped with radar, GPS, and vidcams, as well as a public address system, to give orders to boats that should not be there.
Protector has been used for the last decade 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 can stay out eight hours at a time. The one big shortcoming is that Protector is 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 2009 and 2012 wars with Hamas.
The U.S. Navy had earlier developed the lighter Spartan Scout USV. The Spartan Scout is a two ton, 7 meter (22 foot) long, radio controlled boat. It is armed with a .50 caliber machine-gun and a number of sensors (mainly day and night vidcams). Spartan Scout is more suitable for patrolling port areas and inland waterways.
Both USVs can operate without an operator (by using GPS to move between specified locations). Spartan Scout can stay out for up to 48 hours depending on how much high speed (it can hit up to 80 kilometers an hour) running is done. It also has a loudspeaker and microphones, so that the operator (who is usually so far away that he can't see the USV) can converse with crewmen on small ships. Spartan Scout was particularly useful when it got its first tryout in the Persian Gulf during late 2003. There are a lot of small boats moving about, some of them up to no good. An Arab linguist on the mothership was able to interrogate suspicious boats the Spartan Scout ran down. The civilian sailors were somewhat taken aback when they were interrogated by this Arab speaking boat that had no one aboard. While Spartan Scout was developed primarily to work with the new LCS (Littoral Combat Ship), every ship now wants one or more of them, just for port security.
Spartan Scout is also designed to use different sets of equipment for different missions (detecting mines, Intelligence-Surveillance-Reconnaissance, Anti-Terrorism/Force Protection, destroying threats with the machine-guns, and Antisubmarine Warfare).
Seeing the need for a larger USV, the U.S. Navy has developed a new USV (unmanned surface vessel) to be used by its LCS (Littoral Combat Ships) for anti-submarine warfare. Officially called the Fleet class Anti-Submarine Warfare Unmanned Surface Vehicle (ASWUSV), the 12.5 meter (39 foot) long boats weigh 8.5 tons and can carry 2.5 tons of sensors and other equipment. The USV can move up to 63 kilometers an hour and stay at sea for up to 24 hours and most of the time it would be moving slowly, using its sonar to search for subs. The ASWUSV is equipped with GPS and a computerized navigation system that allows it to automatically run search patterns. Thus the sailors controlling the boat remotely can move it to an area that helicopter or aircraft dropped sonobuoys have picked up a contact and pursue it more intensively with the more powerful sensors it has on board. Such pattern searching (worked out with algorithms derived from experience with what subs can do) has been a successful tactic since World War II. While two of these ASWUSVs can be carried by LCS ships, the boats can also be used from shore stations. The ASWUSV was developed based on experience with the Spartan Scout.