In maritime salvage law, the classification of abandoned or lost goods at sea dictates ownership rights and salvage awards. These classifications—flotsam, jetsam, lagan, and derelict—have centuries of legal precedent behind them. Flotsam refers to goods floating on the surface of the water as a result of a shipwreck or a vessel sinking.
Crucially, flotsam was not deliberately cast overboard; it was washed into the sea by the disaster itself. Jetsam, on the other hand, describes cargo or equipment intentionally thrown overboard (jettisoned) by a crew attempting to lighten a ship in distress to prevent it from sinking. Lagan (sometimes spelled ligan) refers to goods that were deliberately cast overboard, like jetsam, but with a buoy or cork marker attached so the owners could relocate and recover them later.
Derelict applies to a vessel or its cargo abandoned at sea by its master and crew without hope of recovery (sine spe recuperandi) or intention to return (sine animo revertendi). In historical admiralty jurisdictions, such as under English law, these distinctions governed whether found items belonged to the Crown, the original owners, or the salvors who recovered them. If the original owner does not claim flotsam, jetsam, or lagan within a year and a day, ownership traditionally reverts to the Sovereign or state, though the finder who salvages the material is generally entitled to a salvage reward proportional to the risk and value of the saved property.