Seen in Southern Spain. There were literally thousands of them over a huge area of land.
Bit big for my 30 footer but for someone with a bigger boat, I'm sure any offer would be considered !!
There's a similar huge pile of ex-trawler scrap behind the fish shed at Kinlochbervie, a big pile of those weights that trawlers use to keep their nets down (don't know what they are called). No sign of the boats though.