6. What is the difference between 'flotsam' and 'jetsam'?
Although they sound suspiciously like two of Santa's missing reindeer, flotsam and jetsam are actually two different types of debris associated with ships. We rarely hear either term mentioned without the other close behind (and saying 'jetsam' before 'flotsam' is like saying 'Cher' before 'Sonny'). When we talk about 'flotsam and jetsam' today, we are usually referring metaphorically to the unfortunate (for example, 'While visiting the homeless shelter, the governor glimpsed what it is like to be the flotsam and jetsam of our society').
At one time, however, 'flotsam' and 'jetsam' not only had different meanings, but carried important legal distinctions. In English common law, 'flotsam' (derived from the Latin flottare, 'to float') referred specifically to the cargo or parts of a wrecked ship that float on the sea.
'Jetsam' (also derived from Latin — jactare, 'to throw') referred to goods purposely thrown overboard in order either to lighten the ship or to keep the goods from perishing if the ship did go under.
Although the main distinction between the two terms was the way the goods got into the water, technically, to become jetsam, the cargo had to be dragged ashore and above the high-water line. If not, the material was considered flotsam, which included all cargo found on the shore between the high- and low-water lines.
Actually, two more terms, 'lagan' and 'derelict,' were also used to differentiate cargo. 'Lagan' referred to any abandoned wreckage lying at the bottom of the sea; 'derelict' was the abandoned ship itself.
While insurance companies today have to pay out for flotsam, jetsam, lagan, and derelict, the old distinctions once dictated who got the remains. Jetsam went to the owner of the boat, but flotsam went to the Crown. The personal effects of nonsurviving crewmen could become flotsam or jetsam — depending on how far the debris traveled and whether it floated.