以上三个单词都可在海商法中用于指海上的漂流物。其中， lagan (也称为 lagend; lagon；ligan；ligen；lagan)(系标投弃物）和jetsam (投弃物）都是指船舶遇到风暴或其他危险时为减轻船载而故意投向大海的货物（goods deliberately thrown over to lighten ship)。区别在于lagan是指货主为今后寻找到它们，故在货物上系有浮标(Goods cast into the sea tied to a buoy so that they may be found again by the owner)的投弃物[1]。 jetsman 则属于完全放弃情况下未系标志的投弃货物；在英国，jetsman如被重新发现，除原所有人有权请求偿还外，应属于国王所有[2]。flotsam (海上漂流物）（也称为floatage; flotage)除包括为减轻船载而有意投弃的货物外，还包括失事船舶中漂出的物品（goods which float upon the sea when cast overboard for the safety of the ship or when a ship is sunk)[3]，若在一年零一天内货物所有人不予认领，该货物即归王室所有。

[1] Cf. Daphne Dukelow, The Dictionary of Canadian Law，at p. 561, Thomson professional Publishing Canada (1991 ).

[2] "Various legal authorities at various times have attempted to distinguish jetsam from flotsam and lagan by restricting the use of this term either to jettisoned material that floated a shore or to jettisoned material that sank and was not attached to a buoy. ” Cf. James E. Clapp, Random House Webster’s Dictionary of the Law, at p. 251，Random House (2000).

[3] Cf. The Publishers Editorial Staff, Black's Law Dictionary, abridged 6th edition,  at p. 443, West Publishing Co. (1991).