We have done anchoring in places like the Tuamotus where it is extremely hard to avoid bommies and coral, and we hated doing any damage and always tried to drop in sand. We did the toing and froing to unwind the chain successfully each time.
We are now in the Med and have been in the Balearics and currently Corsica.  When in Ibiza we anchored off a sandy beach - the cruising guide warned of rock in the middle. Having dropped in sand we fell back to dig in and got the chain in the midst if some rock.  Thinking it was better to re-anchor straight away, we had the devil if a job freeing the chain and I thought I may have to dive on it - not a pleasant prospect as the sea was full of jelly fish.  Anyway we eventually got recovered the chain and anchor. 
We no longer anchor in any place where the cruising guide says rocky seabed.
The irony us that we carried an enormous Fisherman anchor around the world just in case ... and gave it away to friends who were heading for the Pacific. 
Our main anchor is a Manson Supreme and we also have a Delta and a Fortress.  Should I try to get my Fisherman anchor back or simply carry on staying away from rocky bottoms?