We were drifting off Indonesia when a large thermocol float passed close down the ship’s side.
A little later, I was told it was no longer visible. That was what made me uneasy. If it had simply drifted clear, we should still have been able to see it astern.
We checked aft and noted that the float had become trapped, with a substantial rope reaching the propeller area.
I wrote up the incident and some of the practical considerations here:
Would be interested to hear if others have encountered similar gear in Indonesia or elsewhere.