Shipwreck

For example, extreme cold (such as in a glacial-fed lake) can lead to slow degradation of organic ship materials.
Salvage of wrecks
Often, attempts are made to salvage recently wrecked ships to recover the whole or part of the ship, its cargo, or its equipment. A good example of this was the salvage of the Kaiserliche Marine High Seas Fleet at Scapa Flow in the 1920s. The unauthorized salvage of wrecks is called wrecking.