I hooked the anchor back on the chain and then took it under a large overhang and wrapped the chain around a large horizontal rock.
We later observed the boat attempting to free its anchor and then break the rope. Numerous people saw what happened and all agreed with what I did.
I'm sure that they did! Sorry you couldn't find more here, but I guess you found a few....
So, back to my question. What are you going to do to make sure that particular underwater hazard never puts you at risk in the future?
Not sure how thing go in Australia, but here in the US, armed people sometimes escalate things when they feel that they are in the right and they have been wronged. We just had a guy shoot and kill another guy in a movie theatre for texting during a preview and throwing popcorn at him.
I used to do a lot of road biking, and some messenger wannabes used to carry a small metal punch with them. If a car got too close to them, they would ride next to it, and click the punch on a side window, shattering it, then turning against traffic to ride away and escape. Me personally, I don't pick fights like that.
Try to see it from the other side. You may be very attuned to bubbles in the water, but boaters aren't necessarily the same. As far as he was concerned, he was operating completely within the laws of the land (as you feel you were), and some diver stole his anchor. (I mean, I don't think that he saw you and deliberately tried to kill you). Do you think that will make him more or less concerned about divers in the future?