Mooring Balls - a Good Thing!
Yeah, the mooring ball is attached to a chain which runs down to a heavy weight (usually a very heavy concrete block), auger device or submerged piling which acts as the anchor. The other end has a line coming off of it which you pick up and tie off to. In the image below, note how the owner has tied a bridle off to the ball - providing two points of load transfer. Note also the snubbers tied into the lines to reduce the amount of shock the mooring lines pass to the boat's deck cleats.
Mooring balls are common in areas where people keep their boats where there is no dock or pier - they are also very common in protected areas where the authorities do not want people using their anchors (like near coral reefs, or marine parks, etc). There is also a difference between public (like near beachs and parks) and private (like in front of waterfront homes) mooring balls. Public mooring balls are typically open - although a fee may be charged by a local ranger, etc - but the private balls are -privately owned- (as in the San Juan Islands, where you will not be greeted in a friendly manner if you tie up to someone else's ball).
Picking up (tying yourself off to) a mooring ball is not difficult - it just takes a bit of practice with a boat hook and slow approach. Be aware, however - that there are also buoys that look like anchor balls - that actually mark caution areas - such as sewage outfalls and obstructions. So, not everything that looks like an anchor ball may be one.
Anchorages (and mooring balls) are typically marked on your navigation charts with small anchors and other indicators, however this may vary by locale. You should should be well versed in all the
aids to navigation however, and should consider purchasing a pilot's guide to your local navigation (has all the symbols, lights, etc for your area).
//sse