MV ''Cory Chouest'' is an ocean surveillance ship leased by the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...

in 1989 and assigned to the Navy’s

Special Missions Program Military Sealift Command (MSC) is an organization that controls the replenishment and military transport ships of the United States Navy. Military Sealift Command has the responsibility for providing sealift and ocean transportation for all US m ...

. ''Cory Chouest'' had all SURTASS equipment removed and was returned to her original owners in 2008 completing nearly 20 years of service.

Construction

''Cory Chouest'' was acquired and modified by Edison Chouest Offshore for use by the U.S. Navy as a modified TAGOS vessel. Originally used as a research platform in conjunction with the , the Cory was later modified to carry an active and passive sonar system. The vessel served until October 2008 when it went off charter.

Mission

The mission of ''Cory Chouest'' is to directly support the Navy by using both passive and active low frequency

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on o ...

arrays to detect and track undersea threats.

Operational history

In January 1991, the ''Cory Chouest'' and ''Amy Chouest'' were used as part of the Heard Island feasibility test, an experiment to transmit low frequency sound through the ocean from

Heard Island The Territory of Heard Island and McDonald Islands (HIMI) is an Australian external territory comprising a volcanic group of mostly barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size ...

in the Southern Indian Ocean as far as both ocean coasts of the US and Canada. The ''Cory Chouest'' was chosen because of its central

moon pool A moon pool is a feature of marine drilling platforms, drillships and diving support vessels, some marine research and underwater exploration or research vessels, and underwater habitats, in which it is also known as a wet porch. It is an o ...

and because it was already equipped with an array of low frequency transmitters. A phase-modulated 57Hz signal was used. The experiment was successful and demonstrated that such sound waves could travel as far as the antipodes. Planned transmissions had been for ten days, although owing to the bad weather conditions and the high failure rate of the transmitter elements, used at a frequency below their design frequency, the transmissions were terminated on the sixth day, when only two of the original ten transducers were still working.

Note

There is no journal entry on ''Cory Chouest'' at DANFS.

References

External links

NavSource Online: Service Ship Photo Archive - MV Cory Chouest

Special Mission Program

Military Sealift Command - Ship Inventory – MV Cory Chouest - Ocean Surveillance Ship
* Gordon D. Tyler, Jr.,″The Emergence of Low-Frequency Active Acoustics as a Critical Antisubmarine Warfare Technology", Johns Hopkins APL Technical Digest, Vol 13, No 1 (1992) p 145.

Ocean surveillance ships of the United States Navy 1974 ships {{US-mil-ship-stub