The People's Liberation Army Navy, also known as the People's Navy, Chinese Navy, or PLA Navy, is the maritime service branch of the People's Liberation Army, and the naval power with the largest amount of ships in the world.
The Rim of the Pacific Exercise (RIMPAC), is the world's largest international maritime warfare exercise. RIMPAC is held biennially during June and July of even-numbered years from Honolulu, Hawaii, with the exception of 2020 where it was held in August. It is hosted and administered by the United States Navy's Indo-Pacific Command, headquartered at Pearl Harbor, in conjunction with the Marine Corps, the Coast Guard, and Hawaii National Guard forces under the control of the Governor of Hawaii.
An underwater glider is a type of autonomous underwater vehicle (AUV) that employs variable-buoyancy propulsion instead of traditional propellers or thrusters. It employs variable buoyancy in a similar way to a profiling float, but unlike a float, which can move only up and down, an underwater glider is fitted with hydrofoils that allow it to glide forward while descending through the water. At a certain depth, the glider switches to positive buoyancy to climb back up and forward, and the cycle is then repeated.
Unmanned underwater vehicles (UUV), sometimes known as 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.
The Naval Oceanographic Office (NAVOCEANO), located at John C. Stennis Space Center in south Mississippi, comprises approximately 1,000 civilian, military and contract personnel responsible for providing oceanographic products and services to all elements within the Department of Defense.
USNS Dutton (T-AGS-22) was an oceanographic survey ship for the United States Navy from the late 1950s through the 1980s. She was launched as SS Tuskegee Victory in 1945, Maritime Commission hull number MCV 682, a type VC2-S-AP3 Victory ship. In her U.S. Navy service, she was named after Captain Benjamin Dutton, Jr., and was the second U.S. Navy ship named in his honor.
A multibeam echosounder (MBES) is a type of sonar that is used to map the seabed. It emits acoustic waves in a fan shape beneath its transceiver. The time it takes for the sound waves to reflect off the seabed and return to the receiver is used to calculate the water depth. Unlike other sonars and echo sounders, MBES uses beamforming to extract directional information from the returning soundwaves, producing a swath of depth soundings from a single ping.
The Pathfinder-class survey ships are owned by the United States Navy and operated by Military Sealift Command for the Naval Oceanographic Office ("NAVOCEANO"). They have mostly civilian crews, including scientists from NAVOCEANO.
USNS Pathfinder is a United States Navy oceanographic survey ship, and the lead vessel of her class. Her mission is to collect acoustical, biological, physical, and geophysical surveys of the world's oceans. This data has many uses, but a primary focus is characterizing the ocean environment in order to improve the U.S. Navy's undersea warfare capabilities.
USNS Bowditch (T-AGS-21) was the lead ship of her class of oceanographic survey ships for the United States Navy. Launched as the SS South Bend Victory in 1945, Maritime Commission hull number MCV 694, a type VC2-S-AP3 Victory ship, she was named for Nathaniel Bowditch, the second U.S. Navy vessel named in his honor. The ship was acquired by the Navy in August 1957 and converted to an AGS at Charleston Naval Shipyard. Named Bowditch on 8 August 1957 and placed in service 8 October 1958 for operation by the Military Sea Transportation Service (MSTS).
USNS Michelson (T-AGS-23) was a Bowditch class oceanographic survey ship of the United States Navy. Launched as the SS Joliet Victory in 1944, Maritime Commission hull number MCV 114, a type VC2-S-AP3 Victory ship, she was named after Albert Abraham Michelson. The ship was reactivated from the James River Maritime Administration Reserve Fleet on 8 February 1958, delivered to the Navy Department at the Philadelphia Naval Shipyard on 8 August 1957 and converted to an AGS by the Charleston Naval Shipyard. USNS Michelson (AGS‑23) was placed in service on 15 December 1958 under the operational control of MSTS Atlantic.
USNS Sgt. George D. Keathley, was a World War II United States cargo vessel that was used for troop transport and later converted to a survey vessel. She was laid down and launched as MS Alexander R. Nininger, Jr., then renamed MS Acorn Knot. She was put into US Army service as USAT Acorn Knot, then renamed USAT Sgt. George D. Keathley. She was transferred to the US Navy and became USNS Sgt. George D. Keathley (T-APC-117), but was later re-designated T-AGS-35. She was leased to the Republic of China, where she served as Chu Hwa (AGS-564). Both Nininger and Keathley were posthumous Medal of Honor recipients.
USNS Impeccable (T-AGOS-23) is an Impeccable-class ocean surveillance ship acquired by the U.S. Navy in 2001 and assigned to Military Sealift Command's Special Missions Program.
USS Fort Worth (LCS-3) is a Freedom-class littoral combat ship of the United States Navy. She is the first ship to be named after Fort Worth, Texas, the 13th-largest city in the United States.
The Seaglider is a deep-diving Autonomous Underwater Vehicle (AUV) designed for missions lasting many months and covering thousands of miles. In military applications the Seaglider is more commonly referred to as an Unmanned Underwater Vehicle (UUV).
The Spearhead-class expeditionary fast transport (EPF) is a United States Navy–led shipbuilding program to provide a high-speed, shallow draft vessel intended for rapid intra-theater transport of medium-sized cargo payloads. The EPFs can reach speeds of 35–45 knots (65–83 km/h; 40–52 mph), and allow the rapid transit and deployment of conventional or special forces, equipment and supplies. The vessels are a part of Military Sealift Command's Sealift Program. The class was previously designated as "Joint High Speed Vessel (JHSV)", and redesignated in September 2015.
USNS John McDonnell (T-AGS-51) was a hydrographic survey ship operated by the Military Sealift Command (MSC) with a contract crew for the Naval Oceanographic Office which assigned a military and civilian hydrographic detachment to conduct coastal surveys. The ship and its sister, USNS Littlehales (T-AGS-52), were replacements for the coastal hydrographic survey vessels USNS Chauvenet (T-AGS-29) and USNS Harkness (T-AGS-32).
USNS Chauvenet (T-AGS-29) was a multi-function survey ship laid down on 24 May 1967, at Upper Clyde Shipbuilding Corp., Glasgow, Scotland. The ship was the second survey ship, Chauvenet (AGS-11) being the first, named for William Chauvenet (1820-1870). He was instrumental in the founding of the United States Naval Academy at Annapolis, MD. The mathematics department of the US Naval Academy in Annapolis was founded by Chauvenet and is housed in Chauvenet Hall. Chauvenet was launched on 13 May 1968, delivered to the US Navy, 13 November 1970 and placed in service with the Military Sealift Command (MSC) as USNS Chauvenet (T-AGS-29). The ship conducted coastal hydrographic and topographic surveys under the technical direction of the Oceanographer of the Navy through the U.S. Naval Oceanographic Office (NAVOCEANO). The ship was assigned to the Pacific for surveys, sister ship Harkness (T-AGS-32) was assigned Atlantic duties, doing so until inactivated in November 1992.
Underwater domain awareness (UDA) is the aspect of maritime domain awareness focused on the underwater sector, including, from a security perspective, sea lines of communication (SLOC), coastal waters and varied maritime assets with reference to hostile intent and the proliferation of submarine and mine capabilities intended to limit access to the seas and littoral waters. The military requirement is not the only motivation for undersea domain awareness. The earth's undersea geophysical activities as they relate to the well-being of humans is also relevant, as monitoring such activities can provide vital clues to minimize the impact of devastating natural disasters.
United States
United States Navy 
