The terms jetsam flotsam, and ligan describe marine debris. Jetsam refers to goods thrown overboard , or jettisoned by the crew of a ship in distress. Flotsam describes goods that are floating on the water without having been thrown in deliberately, often after a shipwreck or accident. Ligan (or lagan), describes goods that are sunk in the sea and have a buoy or floating object attached to it as a mark of ownership so that its owner can find and retrieve it later. The finder of ligan should return it to the owner. However, flotsam and jetsam must be returned only if the owner makes a proper claim. The differences among flotsam, jetsam, and ligan are of importance in maritime law and marine salvage.