https://en.wikipedia.org/wiki/USS_Jimmy_Carter
“Jimmy Carter has additional maneuvering devices fitted fore and aft that allow her to keep station over selected targets in odd currents. Intelligence experts speculate that the MMP may find use in missions as an underwater splicing chamber for optical fiber cables.”
Despite all the undue attention placed on the combat U-Boats and their limited success in sinking merchant ships, the history of submarines is primarily the history of getting in good positions to tap cables or radio frequencies or put people in places.
There is very little need for torpedoes or missiles anymore, outside of creating dramatic scenes in the movies.
https://www.public.navy.mil/subfor/underseawarfaremagazine/I...
>Intelligence, Surveillance, and Reconnaissance (ISR). Submarines provide the nation a crucial intelligence-gathering capability that cannot be replicated by other means. Operated with care and cunning and deploying multiple sensors, submarines can monitor happenings in the air, surface, or subsurface littoral battlespace, providing a complete picture of events across all intelligence disciplines. They are also an intelligence "force-multiplier," providing tip-offs of high interest events to other collection assets. Submarines are able to monitor underwater incidents and phenomena not detectable by any other sensor. Since they are able to conduct extended operations in areas inaccessible to other platforms or systems, submarines can intercept signals of critical importance for monitoring international developments. The unique look-angle provided by a submarine operating in the littoral region enables it to intercept high interest signal formats that are invisible to reconnaissance satellites or other collection platforms. Furthermore, the ability to dwell covertly for extended periods defeats efforts to evade or deceive collection by satellites and other sensors. The intelligence gleaned from submarine operations ranges from highly technical details of military platforms, command and control infrastructure, weapons systems and sensors to unique intelligence on potential adversaries' strategic and operational intentions. Our submarines can provide real time alertment to National Command Authorities on indications of imminent hostilities. And unlike other intelligence collection systems such as satellites or reconnaissance aircraft, submarines are full-fledged warfighting platforms carrying significant offensive firepower.