1) In still air your bridle lines will sink and they can wrap around the chain beneath the ball. They do not unwrap themselves and can chafe through in a storm. You can prevent this with flotation along the entire length of the bridle lines. I use cheap closed-cell split-foam pipe insulation (about $2 for each 6ft section at Home Depot or Lowe's). You can cut the foam into small sections but I like to keep them intact and cover most of the line, because that covering also protects the bridle from UV and marine growth. I replace the foam annually due to marine growth. I also use 3M yellow electrical tape to wrap the foam every few feet. That tape stands up well to UV/water and makes the bridle very visible to other boats when we're off the mooring.

2) There is a type of mooring ball sold with the steel rod that goes through the center. That rod rusts inside the ball and eventually becomes very thin, leading to failure, and there is no way to inspect it. I have seen two boats go on the rocks with the mooring bridle still attached to the eye on the corroded rod. If you have one of those I recommend you replace it with the type of mooring ball that allows the mooring chain to come up through a pipe in the center, and attach your mooring bridle shackles directly to the chain.

3) Make sure the mooring and tackle is inspected at least every 2-3 years. If in doubt replace hardware. Beware of inferior imported chain and shackles. The hardware failure below put a friend's boat on the rocks.