Originally Posted by willk
I tried snap shackles - a couple of them managed to open themselves - I actually saw one do it. It was when the line was twisted and the shackle pushed against the eye it was clipped to. I have used a clove hitch since - it means there are no fixed length fenders to contend with when adapting to different situations.
I can see the possibility of them opening, but so far it's not been a problem.
As I said, for me they're a quick way of putting fenders out when I'm on my own (most of the time). If I'm leaving the boat unattended then I generally add other fenders.