The Challenger Deep is the deepest-known point of the seabed of Earth, with a depth of 10,902–10,929 m (35,768–35,856 ft) by direct measurement from deep-diving submersibles, remotely operated underwater vehicles and benthic landers, and (sometimes) slightly more by sonar bathymetry.
A remotely operated underwater vehicle is a tethered underwater mobile device, commonly called underwater robot.
A midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, from which they are launched and recovered and which provide living accommodation for the crew and support staff.
The Flyvefisken-class patrol vessels are warships of the Royal Danish Navy. The class is also known as the Standard Flex 300 or SF300 class. The five vessels sold to the Portuguese Navy are locally referred as Tejo class.
The AN/SQQ-32 minehunting sonar set (MSS) is a variable-depth mine-hunting sonar system originally developed by Raytheon and Thales Underwater Systems for the United States Navy. It includes two separate active sonar systems to detect and classify mine-like objects on the surface, in the volume, or on the bottom of the sea. The sonar systems are packaged in a single towed body tethered to the ship through a cable providing power and data transmission, with the cable length variable via an electric winch. A hole in the ship extending from the sonar maintenance room (SMR) to the hull allows movement of the towed body in different configurations for maintenance, stowage at sea, and minehunting operations. The towed body can be configured for minehunting by either locking to the bottom of the ship's hull for shallow water operations, or by extending and retracting the tow cable to allow for variable depth sonar (VDS) operations. VDS operations are necessary in deep water due to refraction of the sonar from the various temperature layers present in the ocean; with the sonar positioned in the same thermal layer as the suspected mines the error induced by refraction is minimized. The detect and classify sonar subsystems are independently monitored and controlled by two operators at independent panels working together to find and characterize underwater objects as mine or non-mine like objects.
The Scorpio is a brand of underwater submersible Remotely Operated Vehicle (ROV) manufactured by Perry Tritech used by sub-sea industries such as the oil industry for general operations, and by the Royal Navy and the United States Navy for submarine rescue services. Originally developed by AMETEK Straza of El Cajon, United States, they were subsequently developed by Perry Tritech. Although the design of the original Scorpio is over several decades old, it forms the basis for a current generation of Scorpio-branded ROVs. Scorpio ROVs are named in a sequence following the order of manufacture, such as "Scorpio 17" or "Scorpio 45" which refer to specific ROVs.
Mir were a self-propelled class of deep-submergence vehicle. The project was initially developed by the USSR Academy of Sciences along with Design Bureau Lazurith. Later two vehicles were ordered from Finland. The Mir-1 and Mir-2, delivered in 1987, were designed and built by the Finnish company Rauma-Repola's Oceanics subsidiary. The project was carried out under the supervision of constructors and engineers of the Shirshov Institute of Oceanology.
A towed array sonar is a system of hydrophones towed behind a submarine or a surface ship on a cable. Trailing the hydrophones behind the vessel, on a cable that can be kilometers long, keeps the array's sensors away from the ship's own noise sources, greatly improving its signal-to-noise ratio, and hence the effectiveness of detecting and tracking faint contacts, such as quiet, low noise-emitting submarine threats, or seismic signals.
The People's Liberation Army Navy (PLAN) is the naval branch of the People's Liberation Army (PLA), the armed forces of the People's Republic of China. The PLAN force consists of approximately 250,000 men and over a hundred major combat vessels, organized into three fleets: the North Sea Fleet, the East Sea Fleet, and the South Sea Fleet.
The Type 925 Dajiang with NATO reporting name Dajiang, or 大江 in Chinese, meaning Great River, is a type of naval auxiliary ship belonging to the People's Republic of China. Each ship is usually equipped with up to two Type 7103 DSRV class Deep Submergence Rescue Vehicles (DSRVs). The ship is designed to replace the first People's Liberation Army Navy (PLAN) submarine tender PLANS Mount Tai, and the lead ship of the Dajiang class is the Changxingdao. The Type 925 is a submarine tender that can also be used as a submarine rescue ship, and hence, it is designated as a submarine support ship by Chinese.
Salvage diving is the diving work associated with the recovery of all or part of ships, their cargoes, aircraft, and other vehicles and structures which have sunk or fallen into water. In the case of ships it may also refer to repair work done to make an abandoned or distressed but still floating vessel more suitable for towing or propulsion under its own power. The recreational/technical activity known as wreck diving is generally not considered salvage work, though some recovery of artifacts may be done by recreational divers.
The Sea Pole class bathyscaphe is a class of bathyscaphe of the People's Republic of China (PRC). They are capable of diving up to 7,000 meters, covering 99.8% of the oceanic floor of the world. Two units of this class are planned, with derivatives to follow and are used by both the civilian and military establishments in China.
The Chinese 8A4 class ROUV is a remotely operated underwater vehicle (ROUV) used to perform various underwater tasks, ranging from oil platform service to salvage and rescue missions. The 8A4 is a member of a series of related ROUVs developed by the Shenyang Institute of Automation (SIA) in the People's Republic of China (PRC). The predecessor to the 8A4 was the RECON-IV, an improved version of the American RECON-III. The 8A4 itself is an upgraded version of the American AMETEK 2006, and the 7B8 is an improved version of the 8A4.
Sea Dragon (海龙) class remotely operated underwater vehicle (ROUV) is a class of Chinese remotely operated vehicle (ROV) used to perform various underwater tasks ranging from oil platform service to salvage and rescue missions, and it is a class of ROUV developed in People's Republic of China (PRC) with diving capability up to 3,500 meters. After its successful development, a series of ROUVs have been based on the experience gained from Sea Dragon.
Explorer autonomous underwater vehicle (AUV) is a Chinese AUV developed in the People's Republic of China (PRC),first entering service in November 1994. It should not be confused with another two Anglo-American AUVs that share the same name: the American Autonomous Benthic Explorer AUV (ABE) built by Woods Hole Oceanographic Institution, and the British Columbia-based International Submarine Engineeringbuilt Canadian Explorer AUV, which is based on its earlier ARCS AUV.Many Chinese AUVs later developed, such as Wukong, WZODA, CR series, Exploration series, Micro Dragon series, Sea Whale series, Submerged Dragon series AUVs, are all based on experienced gained from Explorer AUV.
The SJT class are remotely operated underwater vehicles. They are a series of Chinese ROVs, jointly developed by the Shenyang Institute of Automation of the Chinese Academy of Science, and the Institute of Underwater Engineering of Shanghai Jiao Tong University (SHJTU). The general designer of the SJT class of ROVs is Zhu Jimao (朱继懋), a professor at SHJTU, who also was the general designer of the earlier Type 7103 DSRV. Many more ROUVs have been developed after the SJT series, based on experience gained from this series.
Underwater work is work done underwater, generally by divers during diving operations, but includes work done underwater by remotely operated vehicles and crewed submersibles.
The Safeguard class is a class of Towing, Salvage and Rescue Ship under the United States Navy.
Deepinfar unmanned underwater vehicles (UUV)s are uncrewed vehicles developed in the People's Republic of China (PRC) by Deepinfar, most of which are in service with various Chinese governmental agencies/departments, and government-owned enterprises.
An underwater survey is a survey performed in an underwater environment or conducted remotely on an underwater object or region. Survey can have several meanings. The word originates in Medieval Latin with meanings of looking over and detailed study of a subject. One meaning is the accurate measurement of a geographical region, usually with the intention of plotting the positions of features as a scale map of the region. This meaning is often used in scientific contexts, and also in civil engineering and mineral extraction. Another meaning, often used in a civil, structural, or marine engineering context, is the inspection of a structure or vessel to compare actual condition with the specified nominal condition, usually with the purpose of reporting on the actual condition and compliance with, or deviations from, the nominal condition, for quality control, damage assessment, valuation, insurance, maintenance, and similar purposes. In other contexts it can mean inspection of a region to establish presence and distribution of specified content, such as living organisms, either to establish a baseline, or to compare with a baseline.
People's Liberation Army Navy 