Re: Yikes! Mooring System Failure
Maine Sail provided a very good list of suggestions as always. The only thing that I would add is that there are many types of swivels and they are not created equal. The two main differences are the eyes and how they are attached. I like solid eyes which you need to put a shackle into as they are by far the most secure. I would never rely on one with a pin held in by a cotter pin, these are fine in applications where they are inspected regularly and there is no corrosion but they are inappropriate for moorings.
Regarding how the two halves of the swivel are attached, it is done in many different ways including peening a stud over, a nut, a welded nut, and welding. I like a nut that is thoroughly welded on the best. as there is a lot of meat there. I remember seeing a good writeup comparing the types but I unfortunately don't remember where it was.