the.com/flotsam

Shipwreck debris that floats by accident, not on purpose — that's jetsam's job.

means Floating wreckage or debris from a ship or its cargo, scattered by accident rather than thrown overboard on purpose.

from From Anglo-French 'floteson,' built on 'floter' (to float), itself related to Old Norse and Germanic words for flowing water — the same watery root behind 'float' and 'fleet.' It entered English through maritime law, which needed a precise word for wreckage found drifting at sea, as distinct from 'jetsam' (from 'jettison') — goods deliberately cast overboard to lighten a ship in distress. The distinction mattered because ownership and salvage rights differed depending on whether the sea took the cargo or the sailors did.

legal distinction
flotsam stays yours, jetsam you deliberately ditched
etymology
from french floter, to float
third category
lagan is debris marked and sunk, not floating
common phrase
flotsam and jetsam means miscellaneous useless stuff
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