Moorings are like permanant anchors that stay in the water rather than come with the boat.
They come in different shapes and sizes. Here’s a typical local configuration, bottom-up.
On the ocean floor is a mushroom anchor, a heavy metal anchor shaped like an upside-down mushroom. Our home mooring weights 1,200 lbs (545 kg). Next comes a length of heavy chain, 15 ft (5 m) in our case, called navy chain. This chain lays on the ocean floor providing additional weight, and causing the mushroom anchor to lie down so its flanges can dig into the mud better. It also works as a shock absorber. If a strong wind or current blows the boat away from the mooring, the heavy chain lifts and lowers smoothly, rather than the boat tugging directly on the mushroom anchor.
In other regions without good mud, heavy blocks of cement are used in lieu of mushroom anchors. Another variant is a an auger that’s screwed into rock.
Next comes a length of light chain, roughly the length of the highest expected tides, connecting the buoy to the heavy chain.
The buoy itself is a floating ball with hardware to attach it to the light chain, and to pennants (lines between the buoy and the boat). Our buoy is called a “bird nest” because there’s a recessed area on the top into which the pennants can be placed when away. This keeps them dry and avoids accumulating algae and marine animals.
The pennants are the lines that are picked up and attahed to the bow cleats of the boat. These are lenghts of heavy rope with eye splices at the boat ends. They are usually surrounded by floats to keep them on the surface. This facilitates picking them up, and keeps them from fouling the propeller should they find their way under the boat.
Optionally, there is a smaller line connecting the end of the pennant to a pickup float with a long vertical stick called a pickup stick. It makes it easier to pick up the pennants. Rather than reach overboard with a boat hook, a crewmember can stand comfortably on the deck and pull up the stick. Note that in the illustration above, the pickup float is attached to the mooring ball. Normally, it’s attached to the penants. Also, this illustration does not include a pickup stick.
In Falmouth, where our home mooring is, a mooring permit must be obtained for a modest annual fee. It assigns a unique number to the mooring.
There are several service companies that help select and source the mooring gear, set it up initially, and maintain it. This includes hauling it out each Fall, storing it over the winter, and redeploying it each Spring. Only the buoy and penants are removed out. A smaller float is attached to the light chain to keep it at the surface, and to mark the spot for the following season.
The service also includes performing an obligatory inspection of the entire setup every two years.