RV ''Horizon'', ex Auxiliary Fleet Tug ''ATA-180'', was a

Scripps Institution of Oceanography Scripps Institution of Oceanography (SIO) is the center for oceanography and Earth science at the University of California, San Diego. Its main campus is located in La Jolla, with additional facilities in Point Loma. Founded in 1903 and incorpo ...

research vessel from 1949 through 1968. During that time she made 267 cruises and logging spending 4,207 days at sea.

Construction

''ATA-180'' was launched 14 July 1944, was commissioned 27 September 1944 and served in the Asiatic-Pacific Theater. She was laid up in the Pacific Reserve Fleet and stricken from the

Naval Register A Navy Directory, Navy List or Naval Register is an official list of naval officers, their ranks and seniority, the ships which they command or to which they are appointed, etc., that is published by the government or naval authorities of a co ...

in 1948.

Service history

As a tug the ship had an obscure history, without an entry in the

Dictionary of American Naval Fighting Ships The ''Dictionary of American Naval Fighting Ships'' (''DANFS'') is the official reference work for the basic facts about ships used by the United States Navy. When the writing project was developed the parameters for this series were designed to ...

and only the bare facts of her construction and deployment. The only mention of ''ATA-180'' on the

Naval History and Heritage Command The Naval History and Heritage Command, formerly the Naval Historical Center, is an Echelon II command responsible for the preservation, analysis, and dissemination of U.S. naval history and heritage located at the historic Washington Navy Yard ...

web site is listing as part of Task Unit 1.2.7 (Salvage Unit) at

Operation Crossroads Operation Crossroads was a pair of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity on July 16, 1945, and the first detonations of nuclear devices sinc ...

. The ship became notable in her second career as one of the trailblazing postwar oceanographic research vessels beginning with her conversion in 1949.

Research career and significance

The ship was notable in the early days of national oceanography following World War II when small converted vessels began multiple expeditions for educational institutions, often under Navy sponsorship. Henry W. Menard notes "It is a rare senior oceanographer anywhere in the world who has not at least seen the ship" and compares her to the Soviet ''Vityaz'' and French ''Calypso'' active during the period. ''Horizon'' made the first of Scripps' deep sea expeditions, a joint Scripps Institution of Oceanography-US Navy effort in 1950 given the name Midpac, during which it was discovered that the sea floor was young. This discovery changed the conception that the sea floor was old and sediment filled and was an early lead to the current

Plate Tectonics Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...

theory The ship was engaged in Scripps' Capricorn Expedition jointly sponsored by the U.S. Navy and University of California, which included echo sounding, seismic and magnetic data collection, coring and heat flux measurement among other tasks. The ship developed a detailed description of the Capricorn Seamount on the eastern flank of the

Tonga trench The Tonga Trench is an oceanic trench located in the southwestern Pacific Ocean. It is the deepest trench in the Southern hemisphere and the second deepest on Earth after the Mariana Trench. The fastest plate-tectonic velocity on Earth is occurri ...

where lies the

Horizon deep The Tonga Trench is an oceanic trench located in the southwestern Pacific Ocean. It is the deepest trench in the Southern hemisphere and the second deepest on Earth after the Mariana Trench. The fastest plate-tectonic velocity on Earth is occurr ...

named for the vessel. The ship's name is given to the Horizon

Guyot In marine geology, a guyot (), also called a tablemount, is an isolated underwater volcanic mountain (seamount) with a flat top more than below the surface of the sea. The diameters of these flat summits can exceed . Guyots are most commonly fo ...

(), Horizon Deep (), Horizon Channel (), and the Horizon Bank (). ''Horizon'' and ''Argo'' discovered and explored the Horizon Ridge ( – ) during the 1962 Lusiad Expedition, a part of the

International Indian Ocean Expedition The International Indian Ocean Expedition (IIOE) was a large-scale multinational hydrographic survey of the Indian Ocean which took place from September 1, 1959, to December 31, 1965, Jawaharlal Nehru then PM of India inaugurated International Indi ...

(IIOE).

References

External links

* * – Research fleet (''Vityaz'') * – ''Vityaz'' photos {{DEFAULTSORT:Horizon Research vessels of the United States