I’ve done a number of dives, and the strangest thing I ever saw was a large deep freezer with a heavy industrial chain wrapped around multiple times with about 5 cinder blocks attached. It was very very rusted and the deep freezer itself had to have been 30+ years old, probably more. This was about 90 feet deep just off Vancouver Island, Canada.
The situation gave myself and the other divers the newbie jeebies. Logged the gps and depth co-ordinates and notified the police. We were able to find out what was inside, since one of the divers had friends with local police. 10 porcelain dolls….