{{Use dmy dates|date=August 2019}} {{Infobox ship |section1={{Infobox ship/image |image=USS ATA-180.jpg |image_caption=USS ''ATA-180'' }}

|section2={{Infobox ship/career |hide_header= |country=United States |flag={{shipboxflag|US|1949}} |name=''ATA-180'' |owner= |namesake= |ordered= |builder= |laid_down= |launched=14 July 1944 |acquired= |commissioned=27 September 1944 |decommissioned= |in_service= |out_of_service= |struck=1948 |reinstated= |honours= |honors= |fate= |notes= }}

|section3={{Infobox ship/career |hide_header=title |country= |flag= |name=''Horizon'' |owner=Scripps Institution of Oceanography |namesake= |ordered= |builder= |laid_down= |launched= |acquired=1949 |commissioned= |decommissioned= |in_service= |out_of_service= |struck= |reinstated= |honours= |honors= |fate=Sold c.1968 |notes= }}

|section4={{Infobox ship/characteristics |hide_header= |header_caption= |class= |displacement=835 t.(lt) 1,360 t.(fl) |tonnage={{GT|505}} |length={{convert|143|ft|abbr=on}} |beam={{convert|33|ft|10|in|abbr=on}} |draught= |draft={{convert|13|ft|2|in|abbr=on}} |power=*2 × GM 12-278A Diesel-electric engines *Fairbanks Morse Main Reduction Gear |propulsion=Single screw {{convert|1200|shp|abbr=on}} |speed={{convert|12|kn}} |range={{convert|7000|mi|abbr=on}} |complement=45 |sensors= |EW= |armament=*1 × 3"/50 dual-purpose gun mount *2 × 20mm AA gun mounts |armour= |armor= |aircraft= |aircraft_facilities= |notes= }} }}

'''RV ''Horizon''''', ex Auxiliary Fleet Tug '''''ATA-180''''', was a Scripps Institution of Oceanography research vessel from 1949 through 1968. During that time she made 267 cruises and logging {{convert|610522|mi}} spending 4,207 days at sea.<ref Name=uclib>{{cite web |url=http://content.cdlib.org/view?docId=kt238n98g2&doc.view=frames&chunk.id=d0e58&toc.depth=1&toc.id=&brand=calisphere |publisher=University of California |title=The Research Ship ''Horizon'' |first=Henry W. |last=Menard |date=February 1974 |website=California Digital Library}}</ref>

==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 in 1948.<ref>{{navsource|09/38/38180|USS ATA-180}}</ref>

==Service history== As a tug the ship had an obscure history, without an entry in the Dictionary of American Naval Fighting Ships and only the bare facts of her construction and deployment. The only mention of ''ATA-180'' on the Naval History and Heritage Command web site is listing as part of Task Unit 1.2.7 (Salvage Unit)<ref>{{cite web |url=http://www.history.navy.mil/faqs/faq76-2.htm#anchor90660 |archive-url=https://web.archive.org/web/19990503145041/http://history.navy.mil/faqs/faq76-2.htm#anchor90660 |url-status=dead |archive-date=3 May 1999 |website=Naval History and Heritage Command |title=Operation Crossroads: Composition of Joint Task Force One |at=Task Group 1.2 (Target Vessel Group)}}</ref> at Operation Crossroads.

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.<ref Name=uclib />

''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 theory<ref>{{cite web |url=http://ceo.ucsd.edu/expeditions/midpac/index.html |website=California Explores the Ocean |title=U.S. Navy Electronics Laboratory MidPac Expedition, 1950 |publisher=University of California, San Diego}}</ref> 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 where lies the Horizon deep named for the vessel.<ref>{{cite report |last=Scripps Institution of Oceanography |date=25 February 1953 |title=Shipboard Report, Capricorn Expedition 26 September 1952 – 21 February 1953 |publisher=University of California Scripps Institution of Oceanography |url=https://escholarship.org/uc/item/9fr0r928 |accessdate=20 August 2020}}</ref><ref>{{cite web |last=Shor |first=Elizabeth Noble |title=Scripps Institution of Oceanography: Probing the Oceans 1936 to 1976 |location=San Diego, Calif |publisher=Tofua Press |year=1978 |page=99 |url=https://publishing.cdlib.org/ucpressebooks/view?docId=kt109nc2cj&chunk.id=d2_4_ch04&toc.depth=1&toc.id=ch04&brand=eschol |accessdate=20 August 2020}}</ref><ref>{{cite journal|url=http://store.pangaea.de/Projects/NOAA-MMS/Brodie_1965.pdf|last=Brodie|first=JW|year=1965|title=Capricorn Seamount, south-west Pacific Ocean|journal=Transactions of the Royal Society of New Zealand|volume=3|issue=10|pages=151–185}}</ref>

The ship's name is given to the Horizon Guyot ({{coord|19|40|N|168|30|W}}), Horizon Deep ({{coord|23|15.5|S|174|43.6|W}}), Horizon Channel ({{coord|47|10|N|145|00|W}}), and the Horizon Bank ({{coord|13|10|S|173|35|E}}). ''Horizon'' and ''Argo'' discovered and explored the Horizon Ridge ({{coord|14|55|S|105|52|E}} – {{coord|14|00|S|106|45|E}}) during the 1962 Lusiad Expedition,<ref>{{cite web |url=http://ceo.ucsd.edu/expeditions/lusiad/index.html |website=California Explores the Ocean |title=Lusiad Expedition, 1962 |publisher=University of California, San Diego}}</ref> a part of the International Indian Ocean Expedition (IIOE).<ref>{{cite web |url=http://www.gebco.net/data_and_products/undersea_feature_names/documents/gazet_sept2007.pdf |format=pdf |title=IHO-IOC GEBCO Gazetteer |website=General Bathymetric Chart of the Oceans |date=September 2007}}</ref>

==References== {{reflist}}

==External links== * {{cite web |url=http://gc.ucsd.edu/data/expeds303.html |title=SIO Geological Collections List of Expeditions |publisher=University of California, San Diego |archiveurl=https://web.archive.org/web/20110720075544/http://gc.ucsd.edu/data/expeds303.html |archivedate=2011-07-20}} * {{cite web |url=http://www.ocean.ru/eng/content/view/14/27/ |website=Russian Academy of Sciences |title=About Shirshov Institute of Oceanology}} – Research fleet (''Vityaz'') * {{cite web |url=http://world-ocean.ru/ru/gallery/list.php?ID=6 |title=World Ocean Museum at the port of Kaliningrad |language=ru |archiveurl=https://web.archive.org/web/20120302010004/http://world-ocean.ru/ru/gallery/list.php?ID=6 |archivedate=2012-03-02}} – ''Vityaz'' photos

{{DEFAULTSORT:Horizon}} Category:Research vessels of the United States