I came across this because I read an article about people looting old shipwrecks for the steel.<p><a href="https://www.theguardian.com/australia-news/2021/oct/24/as-metal-pirates-loot-seabed-treasures-there-are-fears-australias-first-submarine-could-be-next" rel="nofollow">https://www.theguardian.com/australia-news/2021/oct/24/as-me...</a>
It isn't only steel [0]. Old, low-background lead is necessary for some instruments.<p>[0] <a href="https://www.theatlantic.com/science/archive/2019/10/search-dark-matter-depends-ancient-shipwrecks/600718/" rel="nofollow">https://www.theatlantic.com/science/archive/2019/10/search-d...</a>