A remotely operated underwater vehicle (ROUV) or remotely operated vehicle (ROV) is a free-swimming submersible craft used to perform underwater observation, inspection and physical tasks such as valve operations, hydraulic functions and other general tasks within the subsea oil and gas industry, military, scientific and other applications. ROVs can also carry tooling packages for undertaking specific tasks such as pull-in and connection of flexible flowlines and umbilicals, and component replacement. They are often used to visit wrecks at great depths beyond the capacities of submersibles for research purposes, such as the Titanic, amongst others.
A survey vessel is any type of ship or boat that is used for underwater surveys, usually to collect data for mapping or planning underwater construction or mineral extraction. It is a type of research vessel, and may be designed for the purpose, modified for the purpose or temporarily put into the service as a vessel of opportunity, and may be crewed, remotely operated, or autonomous. The size and equipment vary to suit the task and availability.
An autonomous underwater vehicle (AUV) is a robot that travels underwater without requiring continuous input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes non-autonomous remotely operated underwater vehicles (ROVs) – controlled and powered from the surface by an operator/pilot via an umbilical or using remote control. In military applications an AUV is more often referred to as an unmanned undersea vehicle (UUV). Underwater gliders are a subclass of AUVs. Homing torpedoes can also be considered as a subclass of AUVs.
Unmanned underwater vehicles (UUV), also known as uncrewed underwater vehicles and underwater drones, are submersible vehicles that can operate underwater without a human occupant. These vehicles may be divided into two categories: remotely operated underwater vehicles (ROUVs) and autonomous underwater vehicles (AUVs). ROUVs are remotely controlled by a human operator. AUVs are automated and operate independently of direct human input.
An unmanned surface vehicle, unmanned surface vessel or uncrewed surface vessel (USV), colloquially called a drone boat, drone ship or sea drone, is a boat or ship that operates on the surface of the water without a crew. USVs operate with various levels of autonomy, from remote control to fully autonomous surface vehicles (ASV).
Katanpää-class mine countermeasure vessels are a class of three multipurpose mine countermeasure vessels (MCMV) ordered by the Finnish Navy. The nearly 250 million euro contract was awarded to the Italian shipyard Intermarine S.p.A. in 2006. Initially, all three vessels were scheduled to be delivered by 2014 and the class was expected to achieve operational readiness by 2015, but there have been various delays and the last vessel was handed over to the Finnish Navy in November 2016.
Avenger-class mine countermeasures ships are a class of 14 ships constructed for the United States Navy from 1987 to 1994, designed to clear mines from vital waterways. The ships have the hull designator MCM.
The Bedok class are mine countermeasures vessels of the Republic of Singapore Navy (RSN). They play an important role in the maritime security of Singapore, ensuring that the Singapore Strait and the sea lanes surrounding Singapore remain mine-free and open to international shipping. It is estimated that closure of Singapore's ports would result in direct trade losses amounting to more than US$1.2 billion daily, posing a serious threat to Singapore's economy. The four ships form the Sixth Flotilla of the RSN.
UAPS20 is an autopilot system that can be installed on an RHIB boat to obtain an unmanned surface vehicle.
The ASW Continuous Trail Unmanned Vessel (ACTUV) is a DARPA funded project launched in early 2010 to develop an anti-submarine drone. ASW is an acronym for Anti-Submarine Warfare. In January 2018 after successful sea trials it was announced that the "Sea Hunter" prototype has transitioned from DARPA to the Office of Naval Research for further development.
Liquid Robotics is an American marine robotics corporation that designs, manufactures and sells the Wave Glider, a wave and solar powered unmanned surface vehicle (USV). The Wave Glider harvests energy from ocean waves for propulsion. With this energy source, Wave Gliders can spend many months at a time at sea, collecting and transmitting ocean data.
The Fleet-class unmanned surface vessel, also called the Common Unmanned Surface Vessel (CUSV) and later the Mine Countermeasures Unmanned Surface Vehicle, is an unmanned surface vessel designed for the United States Navy to be deployed from Freedom and Independence-class littoral combat ships and intended to conduct mine and anti-submarine warfare missions. As of 2012 four units of the class have been built; the first was delivered to the U.S. Navy in 2008.
The REMUS series are autonomous underwater vehicles (AUVs) made by the Woods Hole Oceanographic Institution and designed by their Oceanographic Systems Lab (OSL). More recently REMUS vehicles have been manufactured by the spinoff company Hydroid Inc, which was a wholly owned subsidiary of Kongsberg Maritime. Hydroid was acquired by Huntington Ingalls Industries (HHI) in March 2020. The series are designed to be low cost, they have shared control software and electronic subsystems and can be operated from a laptop computer. They are used by civilians for seafloor mapping, underwater surveying, and search and recovery as well as by several navies for mine countermeasures missions.
Sea Hunter is an autonomous unmanned surface vehicle (USV) launched in 2016 as part of the DARPA Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) program. The ship was christened 7 April 2016 in Portland, Oregon. It was designed and built by Leidos. The vessel continues the line of experimental "Sea" ships, including Sea Shadow, Sea Fighter, Sea Jet, and Sea Slice. Sea Hunter is classified as a Class III USV and designated the Medium Displacement Unmanned Surface Vehicle (MDUSV).
The JARI USV is an uncrewed surface vehicle developed by the China Shipbuilding Industry Corporation (CSIC), specifically between its No. 716 Research Institute, the Jiangsu Automation Research Institute (JARI), and No. 702 Research Institute, China Ship Scientific Research Centre (CSRRC). The uncrewed warship is designed for potential use for the People's Liberation Army Navy and export customers.
Apa (P-121) is a Amazonas-class offshore patrol vessel currently operated by the Brazilian Navy. She was originally named Scarborough (CG51) while she was being built for the Trinidad and Tobago Coast Guard.
Ghost Fleet Overlord is a fleet of test unmanned surface vehicles operated by the U.S. Navy.
REP(MUS) (Robotic Experimentation and Prototyping using Maritime Uncrewed Systems) is an annual experimentation exercise for Unmanned Maritime Systems organized and hosted by the Portuguese Navy, NATO and Faculty of Engineering - University of Porto, co-organized by the European Defence Agency, with the participation of forces from foreign military forces, universities and tech companies. The exercise has the objective of testing different types of unmanned aerial vehicles, unmanned surface vehicles, unmanned undersea vehicles, and unmanned ground vehicles. Today it is the largest UAV testing exercise, with the participation of several NATO countries. In recent years it has been the largest exercise for experimenting with unmanned vehicles in the world.
The Netherlands and Belgium are doing a joint procurement for the replacements of the Tripartite-class/Alkmaar-class minehunters. Each of the two countries is procuring six new mine countermeasure (MCM) vessels, which makes for a total of 12 MCM ships. The new MCM ships, developed by Naval Group, will include a range of unmanned systems including unmanned surface, aerial and underwater vehicles alongside towed sonars and mine identification and neutralization remotely operated vehicles.
The Pulau Fani class is a class of mine countermeasures vessels in service with the Indonesian Navy. Built by Abeking & Rasmussen, the class design is based on the Frankenthal-class minehunter.
Brazilian Navy 
