CURV-21
U.S. Navy deep-ocean ROV for salvage and recovery operations.
CURV-21 is a remotely operated underwater vehicle used by the U.S. Navy for deep-ocean salvage, capable of operating at depths up to 20,000 feet. It is the newest model in the Cable-controlled Undersea Recovery Vehicle series, replacing the older CURV-III with a more compact overall system. At sea, the vehicle can be reconfigured between side-scan sonar search and ROV operations, and it carries two manipulator arms for salvage work. Its modular build allows it to be fitted with mission-specific gear or specialized tool kits, creating a complete search-and-recovery setup. The system is self-contained and can be flown to any location for deployment on available ships, including Powhatan-class tugboats operated by the Military Sealift Command.
The ROV can move in all six degrees of freedom and has automatic controls for depth, altitude, and heading. An integrated Doppler velocity log enables precise 1- and 2-meter movements, as well as cruise control for longer travel. It uses continuous transmission frequency modulation sonar for locating targets and detecting pingers. Two 7-function rate-controlled manipulators handle recovery tasks. The vehicle is equipped with a high-resolution digital still camera, plus black-and-white and color television cameras. Its 36,000-foot umbilical cable is load-bearing, pressure-compensated, and contains .680 fiber-optic and electro-optical lines. The fiber-optic multiplex system can carry up to eight video channels, sonar data, USBL, RS-232/422/485 communications, and navigation data on a single fiber, with two spare fibers for additional sensors. A 400 MHz digital communications network controls the vehicle and leaves room for future upgrades. The system is designed to connect easily with extra sensors or tool packages using standard data formats. For special missions, it can accommodate custom tool packages such as salvage tools, instrument packages, or other mission-specific equipment.
CURV-21 has been used in several high-profile operations. In February 2010, the French BEA chartered a ship carrying the ROV to help search for Air France Flight 447, which crashed in the mid-Atlantic in 2009. In July 2012, after a U.S. Air Force F-16C crashed in the northern Pacific, Navy searchers and Phoenix International spent ten days recovering wreckage using CURV-21.
- Maximum depth
- 20,000 ft of seawater
- Umbilical cable length
- 36,000 ft
- Umbilical type
- Load-bearing, pressure-compensated, .680 fiber-optic, electro-optical swivel cable
- Manipulators
- Two 7-function rate-controlled manipulators
- Cameras
- High-resolution digital still camera, black and white, and color television cameras
- Sonar
- Continuous transmission frequency modulation (CTFM) sonar
- Control frequency
- 400 MHz digital communications network
Lore & Background
CURV-21 has been involved in several high-profile deep-sea search and recovery missions. In February 2010, the French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) chartered a ship with the ROV to support the search for Air France Flight 447, which crashed in the mid-Atlantic in 2009. On 22 July 2012, a U.S. Air Force F-16C traveling from Japan to Alaska crashed in the northern Pacific Ocean; searchers from the U.S. Navy and Phoenix International spent 10 days recovering remnants of the fighter using CURV-21. The ROV also confirmed the wreck of the cargo ship SS El Faro, lost with all 33 crew on 1 October 2015 after steaming into Hurricane Joaquin; its wreck was found at approximately 15,000 ft, and CURV-21 was lowered to positively identify and videograph the hull and superstructure. After the disappearance of the submarine ARA San Juan in November 2017, the U.S. Navy directed CURV-21 to join search efforts, delivering what were described as 'remarkably clear' pictures. Later in August of the same year, a specially mission-equipped CURV-21 cut free the voyage data recorder (VDR) and retrieved it for NTSB analysis.
Reader's Guide
CURV-21 represents a significant advancement in the U.S. Navy's deep-ocean salvage capability, serving as the direct replacement for CURV-III with a smaller footprint while retaining the ability to operate at depths of 20,000 ft. Its modular design and flyaway transportability allow rapid worldwide deployment on vessels of opportunity, including Powhatan-class tugboats. The ROV's ability to switch between side-scan sonar and ROV operations at sea, combined with its two 7-function manipulators and extensive sensor suite, makes it a versatile tool for search, identification, and recovery. Notable achievements include the record recovery of a Navy MH-60S helicopter from 19,075 ft in March 2021, and the salvage of an F-35 Joint Strike Fighter from about 12,400 ft in early 2022. In August 2022, CURV-21 recovered an F/A-18E Super Hornet that blew overboard from USS Harry S. Truman into the Mediterranean Sea. During the 2023 Titan submersible incident, CURV-21 was involved in search efforts, being one of the few ROVs capable of reaching depths of 4,000 m. The system's fiber-optic multiplex system can combine up to eight channels of video, sonar, USBL, and data communications on a single fiber, with two spare fibers available for additional sensors.
Did You Know?
- CURV-21 can operate at depths down to 20,000 ft of seawater.
- It recovered a Navy MH-60S helicopter from 19,075 ft, a record under SUPSALV.
- The ROV was used to cut free and retrieve the voyage data recorder from the SS El Faro wreck.
- Its umbilical cable is 36,000 ft long and contains fiber-optic and electro-optical lines.
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