What is sailing and sail trim like on a cruising cat or tri? To a large extent that depends on your level of sailing expertise, on the boat you sail, and your perspective. Since the basic sailing concepts apply to all types of sailing craft including multihulls, you’ll find the experience similar to monohull sailing with subtle but important differences. Those new to sailing have few preconceptions about how a multihull should perform. They find multihulls relatively easy, forgiving boats to learn on, as they aren’t trying to subdue years of monohull sailing instincts. Becoming proficient at sailing and sailing a multihull become one and the same. While experienced monohull sailors have a firm grounding in the basics of sailing, they need to get over the mindset of always comparing multihull sailing to sailing one-hulled ballasted boats. Once they can do that the process is easy.
The boat you learn on tends to become your benchmark for what multihull sailing is all about, though performance and handling varies remarkably between various designs. Despite the huge strides in market acceptance over the past few years, there is still a tendency to lump all multihulls together. Trimarans are as different from catamarans as are proas to foilers. Even the differences between daggerboard equipped cats and the ones with low aspect ratio keels are noteworthy. If one actually compares different types of multihulls to each other, one would discover larger differences between them than compared to monohulls. Handling and safety aspects are influenced by the design and underwater appendages of multihulls as much as their construction. Some sailors learn on a true cruising multihull, quite a different experience from sailing a high-performance model. Generally speaking the crew’s level of alertness and anticipation must be greater on a faster boat than on a slower one. Forces and loads on hull and rig are directly proportional to the speed. The bottom line is that the crew of the vessel must be able to have full control of the vessel at all times.
Your perspective on what sailing is all about also influences your approach to multihulls. Some sailors feel you really aren’t sailing unless you are cold, wet and tired. If you can relate to those sentiments, you’ll probably be disappointed with sailing a multihull. I personally couldn’t agree more, having always taken great pleasure in the comfortable, protected sailing conditions and quick passages a multihull affords.
Sailing fast and on the level
One of the first things you notice is the lack of heeling on a cruising multihull. There’s no need for constantly bracing yourself and your gear at unnatural angles. When sailing with novices or inexperienced sailors, the large horizontal surfaces of catamarans allow for a safe and stress free sailing environment even in rougher conditions. Trampolines on the foredeck are converted for socializing and are the main attraction for kids, sunbathers and porpoise watchers. Sailing is more comfortable and less tiring, which should translate into more enjoyment and safer operating conditions.
Searching for a downside to level sailing, I’d say there’s a lack of feedback that heeling provides the helmsman. With no appreciable heel and a reduced tendency for weather or lee helm on a multihull, it is more difficult to tell when it is time to reduce sail. You have to rely on boat speed and boat motion relative to the seas. For this lack of feedback at the helms, which is further exaggerated with boats with hydraulic steering systems, some catamarans are equipped with either cable steering via pulleys and quadrants. This in turn, if not installed properly can ad to friction and failure. The very best steering system, especially in combination with lightweight materials seems to be the direct rod steering, which has the most helm feedback of all installations.
Multihulls have no real ability to spill a gust of wind by heeling; they typically translate excess wind energy into acceleration, something that takes a little getting used to. Rapid acceleration is most noticeable on light displacement multihulls with high-performance rigs. I thought I knew what boat acceleration was until I sailed a 31 foot trimaran sport cruiser. She went from 6-7 knots to 12-13 knots in the blink of an eye, quite normal, I later discovered, for high-performance multihulls.
Cruising multihulls not only accelerate quickly, they maintain higher average speeds than monohulls. This also ads to the active safety (the passive safety being: that most properly designed multihulls do not sink). The high average speeds of some larger performance cruisers will allow 250 nautical mile days or more, which permits boat and crew to stay in front or even dodge a weather system. Because of these easily reached, strain-free speeds, travel time of ocean passages can be reduced by as much as 40 percent or more, consequently also reducing the exposure time of inclement weather.
Generally, cruising multihulls, usually equipped with keels, sail about as fast as fast monohulls, only with higher top speeds, so sailing and sail trim is comparable. Some lightweight daggerboard multihulls, however, can easily attain surfing speeds of 20 knots or more without heel or any strain on crew and boat, even under autopilot. Sailing at those speeds is quite different, partly because everything happens much faster. Apparent wind is brought far forward, to the point where a broad reach on a monohull becomes a close reach on a fast multihull, and a beam reach becomes close-hauled sailing. This is why sails for fast multihulls must be very strong and cut much flatter than those of monohulls. Most cruising multihulls on the market fall somewhere in between, so as a rule you can expect to maintain smaller sheeting angles and flatter sails for a given true wind speed.
The multihull motion
While multihulls sail faster, the sensation of speed can be less than on a monohull due to the wide decks and lack of heeling. Multihulls don’t plunge and rise through the waves like a heavy displacement boat. They stay on the surface of the water, so their motion is lighter, quicker and less sustained in one direction. The leading, high tech catamaran builders go to great length of reducing the pitching- speed robbing motion by carefully centering the weights of the boat around its center of gravity, designing voluminous hull extremities and also by reducing all possible weight in the rigging. Still, some long-time monohull sailors miss the steadiness and responsiveness of a keelboat, but most have an easier time with the multihull motion. Others find it just as easy to be seasick on a multihull.
Light displacement sailing
Multihulls have no use for heavy ballast, since their comfort and safety depends on their ability to remain perched on top of the waves. Good performance is linked to the designer’s recommended payload, which is usually relatively light compared to the boat’s displacement. This is one reason many live-aboard multihulls lack sparkling performance, because they’ve been loaded in excess of the designer’s recommendations. This is one of the big dangers of the cavernous insides and abundant locker space of multihulls. They lure inexperienced owners into filling every corner of the boat with their life’s belongings, turning a narrow hulled and fast thoroughbred into a sluggish platform with sometimes even dangerous sailing characteristics. Therefore, when purchasing a multihull it is very important to respect the limitations of a certain design and also understanding the parameters of different boats and ones payload requirements.
You’ll need to get used to the handling of a light displacement boat. The wind will have a much greater influence on boat handling then on a monohull. Therefore the careful design of aerodynamics of a boats super structure, will be as important as its hydrodynamics of the underwater body. This is especially important at high speeds, where windage becomes the main limiting factor of speed. High windage hulls and bulky bridge deck structures are not only a deterrent to the eye but also make harbor handling in high winds challenging. Multihulls can accelerate rapidly and similarly they lose their way quickly upon heading into the wind, much to the chagrin of neophyte sailors as they attempt to anchor, shoot moorings, close with docks, and come about. In general you’ll need to head up closer to your desired stopping point than you would in a ballasted boat (a little unnerving in the beginning), and maintain boat momentum to make good gains to windward and to bring the boat smoothly through a tack.
Most cruising catamarans have either low profile fixed keels (draft typically ranges between 2’4″ to 4’6″) or daggerboards where the draft can vary from less than 2’0″ with boards up to over 8’0″ with boards down (trimarans typically have one centerboard or daggerboard in the main hull). It’s a major adjustment for monohull sailors to cruise on a shallow draft multihull. Numerous monohull sailors find themselves hyper-ventilating the first time they sail fast in five to six foot deep, crystal-clear Bahamian water.
Properly designed daggerboards can improve performance. They are extremely simple to operate and are superior to low aspect ratio keels in their ability to help the boat sail as close to the wind. They reduce leeway by more than half and because of this ability are much safer when on a lee shore. Not only do they produce much greater lift at even speeds below 7 knots but in heavy weather, by retracting the dagger boards, allow the boat to safely slide down steep waves. Most cruising multihulls have drafts of less than 4 feet, permitting them access to snug anchorages. They allow easy beaching and even running the boat onto a suitable shore in emergencies.
Room with a view
Multihulls have lots of room topsides for sail handling and crew maneuvering. Catamarans usually have full-width travelers for the mainsail, and those designs with bridge deck cabins have the added advantage of a saloon area, which is on the same level with the cockpit, providing good visibility of the surrounding water. This allows crew members to stay in touch with those in the cockpit. Most catamarans even have huge sliding doors and windows turning saloon and cockpit into one giant interconnected living space. Forward looking nav stations and push-button autopilots allow steering the boat from below in inclement weather. It’s not unusual for one crew member to help navigate while tending to some domestic chore “below” in the main cabin.
You may find it difficult initially to steer a straight course over the wide foredeck of a catamaran. The secret is to sight over some point up forward that keeps your line of sight parallel with the boat’s centerline. The optimum arrangement, however, is the use of an autopilot to steer the boat. They do not get tired, complain or make errors, although being an electronic device they may fail when you need them most. The multihull with its better tracking ability than monohulls make’s the autopilot’s job easier, permitting its use in rough conditions where monohulls would have to be hand steered.
Years ago multihulls were considered to have poor windward ability, but modern cruising multihull designs exhibit very respectable upwind performance. Those boats with sleek topside profiles, efficient hull shapes, and daggerboards or centerboards point the best. One trick is to not pinch a multihull as you would a heavy-displacement monohull. By falling off just a bit and keeping your sails full, you’ll maintain momentum and higher average speeds, and avoid making excessive leeway. This also increases lift over the daggerboards or keels, since lift increases with velocity.
Maintaining speed is especially important when getting ready to come about, since good momentum helps take you through a tack smoothly. All tris and most performance cruising cats with dagger boards tack with little effort, if you do not forget to leave them down. The balance of the cruising cats with keels now on the market come about less quickly and are more sluggish sailors in general (especially if they have excessive windage), but usually tack without problem. Vintage cruising cats tend to come about in a rather stately fashion. Light winds with choppy seas is always a bit of a challenge, since it’s hard to gather the momentum needed to overcome the seas in those conditions. You might occasionally have to backwind the jib to avoid being caught in irons, but the technique should only be employed if necessary since it tends to slow your progress.
When you’re ready to come about on a multihull, do it decisively, and make sure you are close to the wind but still maintaining good speed. Trim the main hard before tacking. This allows the main to act like the aft section of a wind vane, helping swing the boat into the wind. Find a lull in the waves and bring the helm over smoothly, and keep it there until you approach 45 degrees off the wind on the new tack. At that point slowly reverse the helm to bring the boat onto your new heading. As you pass through the wind, ease the main a bit to reduce the wind vane effect, which is no longer needed, and to allow the main to fill and provide power on the new tack. If you lose momentum during the tack and need to backwind the jib, delay the release of the headsail sheet until the back side of the jib has filled and is pushing the boat off the wind. As soon as you’re well through the wind, but no farther than necessary, release the windward sheet and haul the leeward sheet in quickly to get the boat moving forward again. Always trim the jib first and then the main. Allow the boat to pick up speed before moving close to the wind again.
When close-hauled in a monohull in windy conditions, standard practice is to head up when hit with a gust. This prevents excessive heeling that can result in a knockdown. When sailing clause hauled on a high-performance cruising multihull, luffing up is still the best course of action when you’re temporarily overpowered; falling off can make the boat accelerate rapidly. This will also depend on your heading, sea state and sea room. Generally speaking if one is on an upwind course with the wind forward of the beam it is recommended to luff up if overpowered. Consequently on a reach or run you would fall off. This will reduce the effect of the centrifugal force and help keep the boat under control. Another way to cope with gusts is to use a square-top mainsail; the square top blows off in a gust, serving as an automatic first reef.
You’ll have to allow for additional leeway when going to windward in any shallow draft boat. Besides their safety aspects of heavy weather sailing, daggerboards greatly help reduce leeway by reaching down into deeper water. Recommendations from the builder or designer and your own experience under sail will tell you how much to allow in various sea conditions. On catamarans with a daggerboard in each hull, use both boards down in light winds to give you the most lift. In moderate winds, use the leeward board since it will be in slightly deeper water. As you gain speed or fall off the wind, the daggerboard can be gradually raised; experience on your boat will tell you how much you can comfortably raise the board under various sea and wind conditions. Also, just before taking, lower the leeward board. High speeds can make it difficult to raise the board; you may find you have to reduce speed temporarily to ease the pressure on the board trunk.
Sailing downwind in a multihull is a breeze, with reaching typically a perfect point of sail. When sailing from a close reach to a beam reach or from a beam reach to a broad reach in a multihull, trim the sails as you would for a monohull—ease the sheets until the leeward telltales flow aft evenly. The main difference from monohull sailing is that fast multihulls bring the apparent wind farther forward, so that for a lot of downwind sailing the sails are set as though for a beam reach. Most multihulls have a 7/8 rig and their masts are held up by shrouds, which are attached to chainplates aft of the mast. This setup, although an excellent means of keeping the rig in place, has a disadvantage of creating chafe on the mainsail rubbing against the shrouds, if the mainsail is allowed to be let out fully. Because of the speed of the multihull, the wind is further forward of the beam than on a monohull, therefore this problem is only apparent in very light air and running deep. A neat trick is to be able to raise the dagger boards and by heading upwind one can increase the apparent wind and consequently the speed of the boat, letting the vessel crab slightly sideways towards its destination. Course made good downwind will be thus increased and you will be sooner at your anchorage. Fast cruising multihulls are often seen flying asymmetrical spinnakers with the headsail up, an advantage for racing. Slower cruising multihulls differ less from monohulls when sailing downwind, although flatter sheeting angles are typically needed to maintain proper sail trim.
When the destination is dead downwind, fast cruising multihulls usually “tack” on a broad reach course and jibe 90 degrees through the wind. This technique produces the fastest speeds and best distance made good. Slower multihulls usually sail closer to dead downwind, but with little heel. This typical rolling motion of a monohull is all but eliminated and the tendency to broach is greatly reduced.
Cruising multihull sailors favor asymmetrical spinnakers for downwind sailing in light winds. With a spinnaker sock all the hassles of deployment and bagging are history. They can be used even single-handed. The tack of an asymmetrical spinnaker is supported by a line from each of the outward bows and one from the main bow of a tri or forward beam of a cat. Asymmetrical spinnakers can be set without a pole due to the wide beam of a multihull, although a short pole permanently mounted on the main bow of a tri or the forward beam of a cat allows the tack to be tightened using only one line. When flying a spinnaker on a multihull you need to be aware of when it’s time to reduce sail. Higher boat speeds mean lighter apparent winds, and it’s easy to get caught in true winds too strong for spinnakers. Get recommendations from your boat designer or sail maker on maximum wind speeds for your boat and sailplan. On a fast multihull, heading downwind temporarily de-powers the sails just as luffing up does when going to windward.
When sailing downwind in light winds, trim the spinnaker first by sheeting it in until the sail begins to stall, then ease the sheet until the leeward telltales flow aft evenly. If the headsail can be carried, trim that next in the same manner, then set the main traveler and trim the main.
If your boat has dagger boards, keep the board(s) down partially for a beam reach to minimize leeway, then raise the board(s) gradually as you sail farther off the wind. Experience will tell you exactly where to place the board(s) in various conditions; it’s best to keep a foot or so of board down when running to improve steerage.
Jibing on a monohull must be done under controlled conditions to avoid rigging damage to gear or personal injury. Boat speed is higher than on monohulls, which means that the apparent wind is lower downwind, so the boom and mainsail can swing across with less force and more controlled than on a monohull. Jibing on a multihull is much easier because one has a wide mainsheet track to control the mainsail. Some multihulls don’t even have a track but employ a double mainsheet systems securing the boom from two sides. Just as a mainsheet traveler this setup allows for an infinite number of sheeting angles and mainsail shaping possibilities, but also acts as an automatic preventer for the boom when jibing or running. When jibing a fast cruising multihull from a broad reach, don’t steer down near the wind before the jibe. This reduces boat speed and makes the conditions more similar to a monohull. It’s better to bring the helm over steadily and “tack” through about 90 degrees until you are sailing on the opposite broad reach course. On slower multihulls you’ll need to jibe in a more controlled fashion. Take the slack out of the main as you steer downwind by trimming the mainsheet and by pulling the traveler amidships. Bear away to jibe the mainsail. As the headsail becomes blanketed by the main, jibe the headsail. Ease the traveler and ease the mainsail for your new heading.
Jibing with an asymmetrical spinnaker complicates the process slightly. As the boat passes through the jibe, release the working sheet and allow the sail to be blown outboard, making sure that the sheet is long enough to now act as the lazy sheet. When the wind is on the opposite quarter quickly haul in the new sheet to prevent the spinnaker from wrapping around the forestay. On the new heading make sure the sheets as well as the lines bracing the tack are free and clear.
Multihulls occasionally surf down the backside of large ocean waves under normal sailing conditions. They can sometimes surf at speeds approaching true wind speed, which brings the apparent wind to zero and causes the headsail or spinnaker to temporarily collapse. A spinnaker in this situation may wrap itself around the head stay. If it wraps tightly, you may need to jibe the mainsail to allow it to release itself. When released, jibe back to your original course. You can help prevent spinnaker wrap by temporarily over sheeting until the apparent wind picks up again. Repeated surfing might indicate that you have too much sail up for the wind and sea conditions.
Maneuvering under sail
Maneuvering a multihull under sail in tight anchorages or around docks requires some practice, particularly with cruising cats that lack good crisp helm response. Give yourself some additional time and distance to turn, and be aware of how quickly a multihull can accelerate in a gust or come to a stop once headed into the wind. Play your main and jib just as you would with a monohull.
by Gregor Tarjan