Flotsam is defined as debris in the water that was not deliberately thrown overboard, often as a result from a shipwreck or accident. Jetsam describes debris that was deliberately thrown overboard by a crew of a ship in distress, most often to lighten the ship's load. I like to believe this life ring is flotsam.

Note: Flotsam and jetsam are terms that describe two types of marine debris associated with vessels.