Mooring Fundamentals
At its heart, a mooring is a permanent anchor that, instead of taking with you, is left in place. Because of this, it has to be incredibly sturdy so that it remains in place for all manner of storms. While personal moorings can be customized to the length and weight requirements of your boat, most public or marina moorings have to be ready for almost any boat. They also have to be properly spaced to ensure that no boats swing into each other in wind changes.
Mooring Construction
Though simple in principle and rarely necessary to know in detail, unless you plan on building your own, it is always good to know a little bit about what is going on underneath, and right on, the surface. As we go through the parts of a mooring, know that the key is that the whole system is only as strong as its weakest link. While there are other systems, particularly for rocky harbors, the system described here applies mostly to soft sand or mud bottoms.
Anchor and Bottom Chain
The two parts of the mooring that should almost always be resting on the bottom are the anchor and bottom chain. For mud bottoms, mushroom anchors, on the order of 300 pounds or more, sink into the soft bottom and bury the entire bottom plate.
The bottom chain, sometimes up to an inch thick links, lies on the bottom as well and tends to be about as long as the water is deep at high tide. The reason for this particular measurement is that, even in a storm, you should first have to drag the entirety of the bottom chain off of the bottom before even tugging at the anchor.
Top Chain
The top chain is the connective tissues between the mooring ball and the anchor. This is generally a little thinner, as the mooring ball has to be able to remain floating even when holding it up. Sometimes this is made out of rope, but chain tends to be easier to maintain in terms of growth and wear. The top chain tends to be about 5-10 feet longer than the depth of the water at high tide and is what gives the boat its swing around the, ideally, set bottom chain and anchor.
Mooring Ball, Pickup Stick, and Pennant
The mooring ball itself provides the floatation required to keep the pennant on water level for any boat to come and pick up. It is the connective link between the anchor and the boat and is the most easily identifiable piece of equipment. It can be either a hardshell buoy, normally painted in blue and white, or a softshell, inflatable mark, normally orange.
The mooring ball is shackled to both the top chain and the pennant. The pennant is the rope, normally spliced together and up to 2 or 3 inches of thick, double braided line, which you tie onto your boat. There are specialized bridle pennants for catamarans, which we will discuss in their own section. All the hardware on the seafloor is worthless if you can’t secure this on your boat, so make sure to tie it on properly and ensure that your hardware is suitably reinforced!
Finally, in order to successfully get the pennant onto a boat, most moorings include a ‘pickup’ buoy. This tends to be a small, foam cylindrical buoy, much like a lobster buoy (and occasionally an actual lobster buoy), with a long, thin stick on top and a weight on the bottom, to ensure that the stick is always reachable. Depending on the freeboard of your boat, it is not uncommon to see a 12 foot, or even longer, pickup stick to ensure reachability. It is normally tied onto the mooring pennant with a relatively small line and is not structural. It is a positive feature on most moorings, but some do not have a pickup, which means that you will have to be pretty handy with your boat hook to grab that pennant!
Making your Mooring a Catamaran Mooring
The beauty of the mooring system is that nothing under the water has to change to build a mooring for a catamaran. Everything from the ball down is identical, but changes begin with its positioning and the pennant.
Positioning
One of the key advantages of a mooring field is that, outside of regions with wild and varying harbor currents, in a steady breeze, almost all of the boats will rotate around their individual moorings at the same rate, meaning that you can actually get the moorings relatively close to each other, for the relative circles that you expect the boats to swing in, as you can anticipate them all rotating in roughly the same pattern. Even a couple more moorings is a few thousand bucks in revenue each year to a marina, so this characteristic is valuable.
Catamarans, however, can occasionally buck this trend. Because they are often lighter than keelboats of comparable length, have less draft, and more windage, they tend to swing around in a changing breeze much more quickly than other boats in the harbor. You really don’t want to park your cat in a sea of keelboats, as you might find yourself swinging into other boats left and right, which is a headache for all parties involved. When looking for a mooring, always assume that your cat is going to swing faster so that you don’t end up in too tight of a spot in a shifty breeze.
Pennant: Two Hulls, One Rope? Uh-Oh!
Like everything else that comes with having two hulls, the design of a catamaran makes normally simple things a little bit complicated on occasion. In this particular instance, the problem comes in trying to tie a catamaran up to something off its bow when it has two bows!
Tying the pennant up to only one of the two hulls would create a pretty significant imbalance on the boat, likely causing the boat to turn sideways to the wind. This would greatly increase the windage on the boat, leading to more pressure on the mooring, which could be dangerous, especially in rough weather.
In order to resolve this, there are two solutions, both of which involve a bridle. You must either have a tie down bridle linking the two hulls with some type of ring or tie down point in the middle to attach the singular pennant. This is the common resolution.
The other resolution, which has started to pop up in recent years as catamarans grow more popular, is to have a spliced double bridle pennant attached to the mooring. This has two separate tie down points connected to the mooring, which then allows you to tie down one to each hull, providing a natural bridle directly to the mooring.
If you plan on picking up a mooring for anything more than a few minutes on a catamaran, one of these two is an absolute must.
Catamaran Mooring Maneuvers
Arguably the greatest feature of the catamaran is its maneuverability, and that is on full display whenever approaching a mooring. Because almost all cruising catamarans come with twin engines, your ability to pivot on a dime and to maneuver at low speeds without having to deal with prop walk is unrivaled by any monohull.
With that, you should expect to be able to execute a mooring approach with great dexterity. You even should have the means to recover and reset when you cannot get it on the first try. We will discuss two general approaches to the mooring, the traditional and the reverse. The reverse is generally employed on cats with high freeboards, small crews, and a mooring without a suitable pickup stick.
With both approaches, there are a few ground rules. If you can enter under motor power only, that can make your life easier, so make sure to drop your sails to make your life less complicated, and always come in slower than you think is necessary! Nothing is worse than a mooring ball caught in a prop; it takes a minute to slow down, and, well, quite a bit longer to get a new prop. If you do end up sailing it in, it is probably best to favor the traditional approach and come in from leeward with your sails close to luffing.
The Standard Approach
The standard approach to a mooring involves swinging to the leeward side of the mooring at minimum control speed before turning up with your bow directly at the mooring. A monohull will aim directly at the mooring and run up to grab the pickup buoy, but this is complicated by the likely gap between the bows.
Thus, on a catamaran, the helm and crew (or a particularly sprightly helm) must decide which bow to bring towards the mooring. Upon choosing one, drive up so that the mooring is hugging the inside of whatever hull you’ve agreed on. At this point, the crew should be able to grab the pickup buoy or use a boat hook to grab the line directly from the water. This job requires quick reflexes, so be ready!
Once the line is aboard, either fasten it to your two tie down lines between the two bows or fasten the two ends of the mooring bridle to their respective cleats. Again, using the dual propellers will really help with that final approach to the ball to ensure that it ends up between the hulls, not stuck under one!
The Reverse Approach
While the standard approach is great when you can reach the mooring from one of your bows, it does suffer from two potential flaws particular to catamarans. First, the higher freeboard on cats means that either it will be difficult to grab with a boat hook, or the pickup stick does not reach the deck. Second, mooring becomes a visibility issue, as it is difficult to see once it gets close to one of the bows. Especially in choppy waters, it might be more difficult to see where you need to swing that bow to get it directly over the mooring, so you might find yourself struggling to get to just the right spot.
Due to these two potential issues, many catamaran owners actually prefer to grab the mooring from the stern! Between better visibility, much lower freeboards (think swim platforms), and easier communication between helm and crew, this can often make approaching a mooring much less stressful.
In essence, rather than approaching the mark by swinging to leeward and heading up, this time you approach the mark in reverse from leeward and slowly back towards the mark against the wind and current.
As you get closer, make sure that you have brought a line from the bow back to the stern on the side where the mooring will be. Once someone can grab the pennant or pickup stick, they should run that bowline through the splice on the pennant. That will allow them to use that line to walk the mooring along the windward side of the boat as the boat slowly rotates 180°, either naturally as the crew walks to the bow or with a little help from the engines spinning the boat. At this point, you tie on just as you would if you had approached head-on.
In this approach, it is particularly important to douse any sails, as it will be pretty hard to reverse when going dead downwind! Additionally, while it can seem a little more difficult to back in and then spin around, this is a much easier way to moor with a small crew; additionally, you avoid having to go fishing for the pennant when a pickup isn't available. Some people prefer to both approach and tie up this way all the time, though I would not recommend in anything but calm seas for brief swims.
Hopefully, this has helped you see that there aren’t many differences between mooring a catamaran and mooring any other boat! It just takes a little bit of foresight, a good bridle, and some fancy, dual-engine driving. Happy Sailing!
