The most famous collection of wrecks used for this, at Scapa Flow, are in 12 to 45 metres of water [0]. Not really deep, as the ocean goes. Generally the ships

The most famous collection of wrecks used for this, at Scapa Flow, are in 12 to 45 metres of water [0]. Not really deep, as the ocean goes. Generally the ships are deep enough that it was uneconomic to salvage them before, but not so deep that it's prohibitive to get at them now. The USS Indiana, also mentioned in the article as a source of low-background steel, was never sunk [1]. It seems it was dismantled and meant to be scrapped, but no one got around to recycling the steel. [0] https://www.northlinkferries.co.uk/orkney-blog/wrecks-of-scapa-flow/ https://www.northlinkferries.co.uk/orkney-blog/wrecks-of-sca... [1] https://en.m.wikipedia.org/wiki/USS_Indiana_(BB-58) https://en.m.wikipedia.org/wiki/USS_Indiana_(BB-58)