Also debt. Aircraft and ships can have debt. Buyer MUST buy "free of all debt".
e.g. X has just upgraded his 1980 C/Pa, with new avionics, upholstery, exterior paint. But he can't pay the bill. Aircraft worth £150,000. Unpaid bill of £120,000, + growing interest. Unpaid hangarage/parking.
You buy the plane and the debt.
Better to wait for auction after seizure on court order. Difficult to deal with all the possible creditors, as well as the owner.
Or aircraft is left to rot away. Everyone loses. Especially the poor lawyers, who don't get any work.