One of the most ghastly experiences I ever had was searching the canal in Birkwith during a rescue. I was in full diving gear groping along the bottom in zero visibility looking for a dead body.....and it seemed like every few metres I found an old welly, which I then had to gingerly feel to see whether it had a leg in or not!
There were quite a few in there, so losing a welly is obviously a regular occurance.
Mark