> Knowing nothing of submarines or seafaring, I'm genuinely curious as to what is logged on a ship that may be necessary a decade later?
I noted in another comment that the National Archives say only "deck logs" are retained permanently, and it looks like this site lists what they contain: https://www.history.navy.mil/content/history/nhhc/research/a..., which includes all kinds of things.
Stuff like "Actions [combat]", "Appearances of Sea/Atmosphere/Unusual Objects", "Incidents at Sea", "Movement Orders", "Ship's Behavior [under different weather/sea conditions]", "Sightings [other ships; landfall; dangers to navigation]" seem like they'd be useful for history and other kinds of research.
Stuff like "Arrests/Suspensions", "Courts-Martial/Captain's Masts", "Deaths" seem like the kind of legal records that are typically kept permanently.
Stuff like "Soundings [depth of water]" were probably historically useful for map-making.
I noted in another comment that the National Archives say only "deck logs" are retained permanently, and it looks like this site lists what they contain: https://www.history.navy.mil/content/history/nhhc/research/a..., which includes all kinds of things.
Stuff like "Actions [combat]", "Appearances of Sea/Atmosphere/Unusual Objects", "Incidents at Sea", "Movement Orders", "Ship's Behavior [under different weather/sea conditions]", "Sightings [other ships; landfall; dangers to navigation]" seem like they'd be useful for history and other kinds of research.
Stuff like "Arrests/Suspensions", "Courts-Martial/Captain's Masts", "Deaths" seem like the kind of legal records that are typically kept permanently.
Stuff like "Soundings [depth of water]" were probably historically useful for map-making.