Editing Deep-submergence vehicle (section)

===''Alvin''-class submersibles===
Originally designed for {{Convert|6000|ft|m|abbr=on}} operation, and initially built to a similar design, Alvin and her sister submersibles have been subsequently, independently upgraded.<ref name=mariner>{{cite web |url=https://catalogs.marinersmuseum.org/object/CL28071 |title= Turtle, Bathysphere (DSV-3), 1968, Hahn and Clay Co., Houston, Texas |work=[[Mariners' Museum and Park]] |year=2022 |access-date=18 September 2022 |url-status=live |archive-url=https://web.archive.org/web/20220918093407/https://catalogs.marinersmuseum.org/object/CL28071 |archive-date=18 September 2022 }}</ref>  Utilizing [[syntactic foam]], these submersibles were more compact and maneuverable than earlier [[bathyscaphe|bathyscaphes]] like [[Trieste (bathyscaphe)|Trieste]], although not as deep diving.

; [[DSV Alvin|DSV-2 ''Alvin'']] : Launched in June 1964 with an initial depth capability of {{Convert|6000|ft|m|abbr=on}}; rebuilt in 1973 to {{convert|4500|m|ft|abbr=on}}. Owned by the [[United States Navy]] and operated under secondment by the [[Woods Hole Oceanographic Institution]] (WHOI) where it conducts science-oriented missions funded by the [[National Science Foundation]] (NSF), [[National Oceanic and Atmospheric Administration]] (NOAA) and the [[Office of Naval Research]] (ONR).<ref>{{cite web|url={{Naval Vessel Register service craft URL|id=DSV2}} |title=No Name (DSV 2) |publisher=Nvr.navy.mil |date=1990-10-25 |access-date=2012-03-27}}</ref> ''Alvin'' operates from [[RV Atlantis (AGOR-25)|R/V ''Atlantis'']], an [[AGOR-23]] class vessel owned by the ONR and operated by WHOI under a charter party agreement. In 2004, the [[National Science Foundation]] funded a {{Convert|6500|m|ft|abbr=on}} capable replacement for Alvin, however the key components, such as a new titanium personnel hull, and funding were used to substantially rebuild Alvin in 2011 and 2020 instead.<ref name="2014 return">{{cite web |url= https://www.nsf.gov/news/news_summ.jsp?cntn_id=130226&org=NSF |title=Alvin cleared to return to service |publisher=National Science Foundation |year=2014 |access-date=24 June 2023 |url-status=live |archive-url=https://web.archive.org/web/20230624061518/https://www.nsf.gov/news/news_summ.jsp?cntn_id=130226&org=NSF |archive-date=24 June 2023}}</ref> In 2022, Alvin was certified for 6,500 m operations.<ref name="2022_seatrials">{{cite web |url= https://www.whoi.edu/oceanus/feature/who-is-alvin-and-what-are-sea-trials |title=Who is Alvin |publisher=Woods Hole Oceanographic Institution |year=2022 |access-date=23 June 2023 |url-status=live |archive-url=https://web.archive.org/web/20230325014149/https://www.whoi.edu/oceanus/feature/who-is-alvin-and-what-are-sea-trials/ |archive-date=25 March 2023}}</ref>
; [[DSV-3 Turtle|DSV-3 ''Turtle'']] : ''Alvin''{{'}}s identical sibling, launched in December 1968 and retired 1998. Owned and operated by the United States Navy.<ref>{{cite web|url={{Naval Vessel Register service craft URL|id=DSV3}} |title=No Name (DSV 3) |publisher=Nvr.navy.mil |access-date=2012-03-27}}</ref>
; [[DSV-4 Sea Cliff|DSV-4 ''Sea Cliff'']] : Another ''Alvin''-class DSV sub, launched in December 1968, retired in 1998, and returned to active service in September 2002. Since 1981, ''Sea Cliff'' has a depth capability of {{convert|6000|m|ft|abbr=on}},<ref name=mariner/> and is owned and operated by the United States Navy.<ref>{{cite web|url={{Naval Vessel Register service craft URL|id=DSV4}} |title=No Name (DSV 4) |publisher=Nvr.navy.mil |access-date=2012-03-27}}</ref>
; [[DSV-5 Nemo|DSV-5 ''Nemo'']] : Another ''Alvin''-class DSV sub, launched in June 1970 and retired in 1998. Owned and operated by the United States Navy.<ref>{{cite web|url={{Naval Vessel Register service craft URL|id=DSV5}} |title=No Name (DSV 5) |publisher=Nvr.navy.mil |access-date=2012-03-27}}</ref>