I like a full round turn on the mooring ring - less chafe. These do not accomplish that. In BC the rings are on a chain that you can lift through the mooring buoy. Yes, sometimes they get fouled and you end up picking up the whole thing.
ISPA Yachtmaster Offshore Instructor Evaluator
Sail Canada Advanced Cruising Instructor
IYT Yachtmaster Coastal Instructor
As I sail, I praise God, and care not. (Luke Foxe)