The People's Liberation Army Navy, also known as the People's Navy, PLA Navy or simply Chinese Navy, is the naval warfare branch of the People's Liberation Army, the national military of the People's Republic of China. It is composed of five sub-branches: the Surface Force, the Submarine Force, the Coastal Defense Force, the Marine Corps and the Naval Air Force, with a total strength of 350,000 personnel, including 70,000 marines and 30,000 naval aviation personnel. The PLAN's combat units are deployed among three theater command fleets, namely the North Sea, East Sea and South Sea Fleet, which serve the Northern, Eastern and Southern Theater Command, respectively.
The Royal New Zealand Navy is the maritime arm of the New Zealand Defence Force. The fleet currently consists of nine ships. The Navy had its origins in the Naval Defence Act 1913, and the subsequent acquisition of the cruiser HMS Philomel, which by 1921 had been moored in Auckland as a training ship. A slow buildup occurred during the interwar period, and then in December 1939 HMS Achilles fought alongside two other Royal Navy cruisers at the Battle of the River Plate against the German ship, Graf Spee.
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.
A blue-water navy is a maritime force capable of operating globally, essentially across the deep waters of open oceans. While definitions of what actually constitutes such a force vary, there is a requirement for the ability to exercise sea control at long range.
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.
The Naval Oceanographic Office (NAVOCEANO), located at John C. Stennis Space Center in south Mississippi, is an echelon IV component of the Naval Meteorology and Oceanography Command (NMOC) and 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 swathe 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 Coastal Crusader (AK-220/ORV-16/T-AGM-16/AGS-36) was an Alamosa-class cargo ship that was constructed for the US Navy during the closing period of World War II. She was later acquired by the US Army in 1946 and the US Air Force in 1957 before being reacquired by the USN in 1964 and as a missile range instrumentation ship.
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 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, and allow the rapid transit and deployment of conventional or special forces, equipment and supplies.
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).
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 
