Editing Transponder (section)

===Marine===
The [[International Maritime Organization]]'s [[International Convention for the Safety of Life at Sea]] (SOLAS) requires the [[Automatic Identification System]] (AIS) to be fitted aboard international voyaging ships with {{GT|300 or more|disp=long}}, and all passenger ships regardless of size.<ref>{{cite web
 |work        = [[International Convention for the Safety of Life at Sea|SOLAS]]'1974
 |url         = http://www.imo.org/KnowledgeCentre/ReferencesAndArchives/HistoryofSOLAS/Documents/SOLAS%201974%20-%20Brief%20History%20-%20List%20of%20amendments%20to%20date%20and%20how%20to%20find%20them.html#43
 |title       = December 2000 amendments
 |author      = International Maritime Organization
 |url-status     = dead
 |archive-url  = http://arquivo.pt/wayback/20140725015425/http://www.imo.org/KnowledgeCentre/ReferencesAndArchives/HistoryofSOLAS/Documents/SOLAS%201974%20-%20Brief%20History%20-%20List%20of%20amendments%20to%20date%20and%20how%20to%20find%20them.html#43
 |archive-date = 2014-07-25
}}</ref> AIS transmitters/receivers are generally called ''transponders'', but they generally transmit autonomously, although [[Coast radio station|coast stations]] can interrogate [[Automatic identification system#Detailed description: Class B units|class B transponders]] on smaller vessels for additional information.{{cn|date=May 2024}} In addition, [[navigational aid]]s often have transponders called [[Racon|RACON]] (radar beacons) designed to make them stand out on a ship's radar screen.{{cn|date=May 2024}}

[[Sonar]] transponders operate under water and are used to measure distance and form the basis of underwater location marking, position tracking and [[navigation]].