Shipwreck

However, many legal systems allow the rights of salvors to override the rights of the original owners of a wreck or its cargo. As a general rule, non-historic civilian shipwrecks are considered fair game for salvage. Under international maritime law, for shipwrecks of a certain age, the original owner may have lost all claim to the cargo. Anyone who finds the wreck can then file a salvage claim on it and place a lien on the vessel, and subsequently mount a salvage operation.
Some countries assert claims to all wrecks within their territorial waters, irrespective of the interest of the original owner or the salvor. Wartime wrecks have different legal considerations, as they are often considered prizes of war, and therefore owned by the Navy that sunk them.
Some legal systems regard a wreck (and/or its cargo) to be abandoned if no attempt is made to salvage them within a certain period of time. English law has usually resisted this notion (encouraged by an extremely large maritime insurance industry, which asserts claims in respect of shipwrecks which it has paid claims on), but is has been accepted to a greater or lesser degree in an Australian case and in a Norwegian case. The American courts have been inconsistent between states and at Federal level. Under Danish law, all shipwrecks over 150 years old belong to the state if no owner can be found. In Spain, wrecks vest in the state if not salvaged within 3 years. In Finland, all property on board shipwrecks over 100 years old vests in the state.