An aging steel ship suffering from extensive surface corrosion and poor maintenance. Sailors and dockworkers use the term to describe vessels that look neglected, where the paint has failed and rust streaks bleed down the hull plates. While often an insult regarding the ship's seaworthiness, crews sometimes use it affectionately for an ugly but reliable workboat.
Heard on the job
I can't believe the port state control let that rust bucket clear the harbor with those hull plates.