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Frequently Asked Questions on Multihulls

How Do Trimarans And Catamarans Compare?

Comparing performance of equal size and type boats, the trimaran is faster to windward in all conditions, and faster in light airs. The catamaran can be faster on a reach (except in lighter airs) and both are very similar when running. One of the biggest advantages of the tri is the maneuverability, tacking being far superior.

Overall the trimaran offers better all round performance, and this is reflected in it now being the multihull of choice in ocean racing.

Some minimal open wing deck style catamarans can offer very high performance in favorable conditions, but otherwise they are not very practical boats with very limited accommodation. Trailering can take hours, plus the very tall rigs frequently used can make them more prone to capsize.

A good comparison photo of the Trailertri 680 (22") and a 23' open wingdeck style cat. The
huge difference in accommodation and practicality is very obvious.

Comparing accommodation, the tri is best below 12m (40') while the cat is considerably better above. The tri offers more accommodation in the smaller sizes, while maintaining a consistently better all round performance, but for roomy cruising it is hard to beat the big cat. An accommodation comparison for smaller trailerables

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What About Tacking?

Tacking was a problem with older multihulls, because most of them had no daggerboard. Farrier trimarans with a dagger/centerboard, combined with floats that just skim the water, tack very fast - it can even be done by sails only, without using the rudder! The nice thing about the tri is that it combines the speed of a cat with the maneuverability of a monohull.

Catamarans don't tack as easily, because they don't have a central daggerboard to pivot on, combined with widely spaced, deeply immersed hulls. However, good design, with daggerboards or centerboards, combined with deep rudders can provide quite acceptable tacking.

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How Do Multihulls Point?

Once a common question, but less so now since Dennis Connor's catamaran Stars and Stripes showed how well a multihull can go to weather in the America's Cup. The world's most radical monohull, even though twice the size, couldn't keep up. A trimaran is even faster than a cat to windward.

Older multihulls didn't go to weather well simply because most of them didn't have daggerboards. In general, a Farrier design will go to windward equivalent to a monohull 50 to 60% larger.

Pointing is simply a function of how good the sails are, the sheeting angle, and the size of the daggerboard or centerboard. These being equal, the mono or multi will point exactly the same, but the multihull will be faster through the water.

See also Comparison


Can Trimarans go to windward?

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How Easy is Trailering?

Farrier trimaran designs are one of the easiest and quickest boats to trailer. Particular care and thought have gone into rigging and launching, and there are no other similar size boats that will be faster to launch. Generally it will take less than 30 minutes (except F-36), even single-handed, after a little practice. The record for an F-27 from arriving at the ramp to being on the water and sailing is 14 minutes, with just two people! Needing little water to float, they can also be launched at ramps where many other boats dare not venture.

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F-28 being rigged up

How Do Farrier Trailerable Designs Compare to Others?

The only alternative trailerable multihulls are demountables that require assembly. This normally takes several people and you should check the time required by seeing a demonstration. A 25 footer for instance, will require at least two holding the float up in the air ( min. 100lbs lift for each person) while a third tries to line up the bolts. Observing many such boats has shown that assembly usually takes from two to four hours. A very large demountable, such as the F-36, could take a full day.

A fast multihull is of little value, if even the slowest monohull can get to that distant anchorage faster, due to a two hour head start while one assembles the boat. This rapidly becomes tiresome and such trailerables are soon left on a mooring.

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What About Marina Docking?

Farrier trimaran designs will easily fit in any marina berth that will accept a similar size monohull. There will be some minor cosmetic problems with growth on the lower float sides, but this is of no consequence if it is only being slipped for a short time. However, modern dock lift systems have now even eliminated this factor with long term docking (see Docking).

Being demountable, the F-36 cannot use a marina berth, but its shallow draft enables mooring or docking in areas others cannot use. The F-41 can fit in some wider docks, but will generally require an end tie.

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A Farrier trimaran design can fit just about anywhere when folded

How Was The Farrier Folding System Invented?

Sailing through a fleet of monohull trailer sailers in 1973, while on an early Piver trimaran, it occurred to designer that the trimaran configuration would be ideal for the trailer sailer. It is light for towing, much more stable, totally unsinkable, and it sails much faster. The only problem was how to fold it down for trailering. Several existing systems were investigated, including telescopic beams, straight hinges, and the 'swing wing' system.

Telescopic beams have major binding problems from alignment, or grit, and are seldom used or tried anymore. Straight hinges are major weak points in the actual beams, and don't allow folding on the water.

The 'swing wing' system has structural problems with multiple hinges and the associated wire braces frequently used. The end swages of such wire braces are located just above water level and very susceptible to corrosion, as are the wires themselves. A sudden failure without warning in this area could be catastrophic and life threatening, and thus they must be frequently checked and replaced.

'Swing wing' beams may also rely on the rig to resist reverse loading on the float. During normal sailing, the lower wire braces are in tension and take all loads, but should the float be reverse loaded, then the wires cannot take the resulting compression load, as can the solid folding struts in the Farrier System.

Such reverse loading can occur in large sideways breaking seas, and the rig is down for some reason. This could also result in a complete breakup should the boat ever be capsized and the rig has failed. A multihull's ultimate safety depends on its unsinkability and structural integrity, so a possible breakup if inverted is not a good feature.

After much thought, the system of using separate control struts came as a flash. This solved all the problems and is structurally sound in all conditions. A model was built, then a full size prototype, and the Farrier Folding System has worked perfectly ever since.

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What About Folding System Copies?

The original folding patent has now expired and a few imitations have appeared in some countries. Usually old technology has been copied, and the folding geometry on some is such that it will be impossible for one person to fold.

Some also do not even bother to use plastic bushings between the aluminum folding struts and stainless steel pivot pins. Custom made glass reinforced acetal bushes are always used for this purpose on Farrier designs, and these prevent any corrosion, or even seizure, should the boat not be folded for an extended period.

Beware also of large aluminum structures being embedded in composite, as the different thermal expansion rates of aluminum and fiberglass can cause tremendous stresses within the structure itself.

It would be wise to always see any unproven design launched and working before making a decision.

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How Stable Are Farrier Trimarans?

There has been a general trend towards bigger floats and more beam, resulting in much more stable boats. The latest Farrier designs are also considerably more stable than earlier designs, but care has been taken to ensure that the float shape does not overstress the beams, and windward ability is not lost due to higher windage from excessive beam. Both can create safety, comfort, and performance problems

Correct float design avoids too much fullness at the keel, to give an ability to initially heel a little to help safely absorb unexpected gusts. It also softens the motion through waves, and avoids heavy pounding or shock loads to the beams (and the crew).

Excessive beam quickly adds windage and weight, and such boats then require a larger rig to overcome the extra windage and weight.

The rig itself then adds even more windage and weight. The result is a boat that is slower to windward, and pitches considerably more. It is also more prone to nose diving off the wind, due to the fore and aft stability being poor compared to the much higher sideways stability, yet it still has to handle the larger rig.

Actual race results have frequently shown the cruising orientated F-Series® designs to be very competitive with extreme beam racers, particularly in rougher conditions. They can be driven harder and safer, while providing both room and performance. The reason is the better overall design 'balance' of the F-Series® designs. Wider beam is not necessarily better!

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Is The Cockpit Size Sufficient?

Aft cabin cockpits are smaller than the equivalent monohulls. However, the more stable multihull does not need all the crew sitting out on the windward side, to reduce excessive heel and to keep the boat under control.

In actual practice the crew of a trimaran can sit anywhere on the huge deck area, including the leeward side and quite often the helmsman will be left on his own in the cockpit.

Catamaran cockpit areas are huge in comparison.

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Can Trimaran Floats Be Used For Storage?

Yes, this is possible and they are ideal for storing large bulky items like sails, leaving interior uncluttered.

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Why Aren't Daggerboards Or Rudders Used In Trimaran Floats?

Because they add extra weight and complexity, twice the work in fact, and they just don't work well. It is virtually impossible to steer the boat while folded with rudders on the floats, and the boat can be difficult to control under power with float daggerboards as these also cannot be used while folded. The boat then tends to have a hovercraft like motion, crabbing sideways due to the lack of any lateral area - becomes very difficult to maneuver in any confined locations, or just prior to putting on the trailer. A few boats in Australia and New Zealand have tried such configurations, but soon abandoned them.

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Why Isn't an Outboard Well Used?

While an outboard well such as used on the original F-27 can be very useful, they are difficult to make, and the extra expense and weight required does not justify the advantages. The now readily available extra long shaft motors help avoid the cavitation problem with stern mounted engines, and with many remote control systems now readily available, control of the motor is not a problem with aft cabin versions. Maneuverability in fact will be greater, as the motor can be turned much more than if it were in a well.

Catamarans are different, and the bridgedeck area is an ideal situation for an outboard well, and this can have many advantages..

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Can I Beach a Farrier design?

Sure, you can run right into the beach and pull her hard up on the sand. An alternative method is to pull into the beach, drop off crew etc. and then anchor, just afloat, in knee deep water. You can thus wade out easily, and this avoids unnecessary wear on the hull bottom.

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The advantages of a shallow draft multihull - any beach will do. F-25A shown. Compare beam and stability with the 26' monohull behind.

Are Farrier Designs Ocean Going?

A number of ocean crossings have been made by F-27s, F-28s, F-9As, and F-31s, however they are small boats for such long passages, and for this reason such voyages are not recommended. Only the F-36, F-39 and F-41 are true ocean going designs.

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How Strong Are Farrier Designs?

Some early pioneering multihulls had structural problems, particularly in holding the floats on, due to lack of knowledge of the stresses involved. But this is no longer the case, provided the designer has the experience and an engineering background.

Monohulls have had their own problems over the years, particularly in holding the keel on, and this join is actually under much more concentrated stress than a trimaran float to beam join. But monohulls have been around for decades, the stresses are known, and problems are few, as is the case now with multihulls.

All Farrier designs have been designed for rough Australian conditions which make them tough, and in Australia they now have a reputation of being 'bulletproof'. Boats destined for Australia or other heavy wind areas are not strengthened as they are already strong enough. Safety factors of up to 5:1 are used in structurally critical areas, whereas aircraft typically use 1.5 or 2:1.

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How Safe Are Multihulls?

Farrier designs have an excellent safety record due to their enormous stability, conservative rigs, and unsinkability from many separate watertight compartments, and no heavy ballast. Comparing monohull and multihull, the multihull's ultimate stability position is floating upside down, where it makes a great liferaft. The monohull's ultimate stability position is resting on the bottom where it makes a good fish farm. There's a reassuring sense of security in knowing that no matter what, your boat cannot sink.

However, this unsinkability can be a publicity magnet for any multihull disaster, whereas a monohull sinking attracts little notice as there is no evidence or nothing to photograph left. Thus multihull accidents frequently attract more publicity even though the boat and crew are usually saved, whereas a monohull sinking, with loss of boat and lives, is frequently overlooked.

An F-27 in France with all three hulls flooded in order to receive an unsinkable certification. Note how high it is floating.

In reality, both types of boats are extremely safe, much safer for instance than power boats, jet skis or light aircraft, and only require different handling techniques for different situations.

Capsize is the only significant danger for multihulls, running aground or collision with floating objects being much less serious hazards with the shallow draft, unsinkable multihull. A capsize is considerably less terminal than a sudden sinking, and can be easily avoided by simply reefing and slowing down.

In this regard, the multihull does require a reasonable level of maturity or common sense to operate safely within its limits, as with other modern forms of transport. Performance is not limited by restrictive devices or weight, and one is thus given the choice of going faster when desired. It's the skipper's decision.

With a boat that has a top speed of 25 knots and can maintain averages of over 15 knots, limiting top speed to say 15 knots, or averages to around 10 knots, gives a responsible and very safe margin for secure general family sailing.

The high performance capability means one can also frequently outrun bad weather to be snug and safe in harbor while slower craft have to remain at sea. More information on Safety

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How Should I Choose a Design?

You should compare the designer's record, and experience. Has he built or sailed any of his own designs? Do they actually have a race or sailing record to match the claims?

There is no university or school that teaches multihull design, nor are there scantling rules, as exist for monohulls. The only teacher has been years of practical building and sailing experience.

Only experience will tell the loadings and correct safety factors for the many critical areas of a multihull. A competent engineer may have the skills to design beams that will not break for a given load, but if he doesn't know what that load is, or in what directions it can act, then even the best engineering skills are of little help.

There are a number of excellent multihulls now available, but choose carefully, as this is very important to the safety and security of your family, and the final resale value.

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How Important is Performance?

Performance is an important advantage of the modern cruising multihull, but not the most important. Comfort, handling, room and structural reliability are also very important factors for any modern cruising boat, and performance should not be obtained at their expense.

Almost anyone could design or build a ‘high performance’ multihull, just by underbuilding it for lightness, providing only minimal room, using extreme beam, putting on a huge rig, and there you have it. But such a boat can be structurally unreliable, prone to pitchpoling, and very impractical, with low resale value. The real skill comes in designing a high performance multihull that is also reliable, roomy, practical, able to carry a load, and have an excellent resale value. It should also be able to perform in all conditions, not just off the wind. This is where Farrier designs excel - they may not always be the fastest, but they are always consistently fast, in all conditions, while also providing that very necessary room, comfort, handling, and most important, structural reliability

The best way to establish the true picture of performance is to look at the actual track record of the designs concerned. Some have plenty of claims but no record, while others publish long lists of race wins, many of which are frequently easy downwind races. Check how they fair in tougher upwind events or the more testing light air races. Is there is no record of structural failures or capsizes when conditions get really tough? Can any multihull claim high performance if it is frequently beaten by even monohulls in lighter airs? Check also that any winning boat is not a specially built race special, with an undeclared taller mast or exotic construction.

Don Wigston’s F-28R - race winning performance and a great cruiser

Is High Performance Worth It?

Yes and no. It is not worth it if the cost is an over-rigged and under built boat - too risky, too much trouble, and too expensive. But a boat that can go fast reliably and comfortably has many advantages, as cruising range, safety, and the important fun factor are considerably increased.

For an example, the voyage from Catalina Island to Marina Del Rey in California is usually a 4 to 5 hour trip for most conventional displacement sail boats, and this hardly improves no matter how strong the wind. The best time by a Farrier design (F-27) is 1 hour and 37 minutes. This was with a husband and wife crew, and having fun all the way due to the exhilarating and effortless speed coupled with easy fingertip control. Thus, when the wind is up, one can leave Catalina as late as 4 or 5pm on a Summer night, and be back before dark, whereas everyone else has had to leave at 1 or 2pm.

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What Is The Float Buoyancy Ratio?

The float buoyancy ratio is not a figure that is used for Farrier designs nor does this figure have much importance placed on it. The shape of the floats is a much more important factor for seaworthiness and performance. The ratio also depends on built weight which can vary widely, and the ratio on the F-25, for instance, can range from 120% to 180% depending on what version (for the same float).

Float buoyancy and design are in fact frequently a misunderstood area of trimaran design with low buoyancy floats being generally regarded with suspicion or criticized, while high buoyancy floats are touted as faster and safer.

High buoyancy floats are now used on Farrier designs, but low buoyancy floats were used in all earlier inshore Trailertri designs. Interestingly, these earlier submersible float designs have the best safety record of all Farrier designs, with the lowest wind capsize rate. They have in fact proved very forgiving, even being capable of coming back after a complete near 90 degree knockdown - just like a mono.

The leeward float could actually be frequently submerged at least 1 foot (300mm) completely under for 100 yard (100m) bursts at a time, usually while doing 12 to 15 knots. There are no serious ill effects as often claimed by those without any experience with such floats. The boat just doesn't seem to care. It actually tends to round up more rather than slew off to leeward, or trip over the float. In many years of doing this the beams were never found to stop the boat if the power is kept on and sail setup is correct. The float itself can actually have less drag when completely under.

However, low buoyancy floats are slower overall, as ultimate stability is less, and they tend to act as a governor. Hence higher buoyancy floats are now used on all the latest designs. The other disadvantage of low buoyancy floats is the possibility of tripping when being knocked sideways by large waves offshore. Not a problem with inshore trailerable designs and this can be minimized by the correct float shapes. Tripping has also never occurred, even with some Trailertris that have had to lie ahull off Australia and New Zealand where large waves are common. Not an advisable practice however.

The fallacy that it is an instant disaster for any trimaran to submerge the lee float bow, or even the whole lee float should be put to bed. While it is definitely not a good idea to continually sail on the limit and frequently submerge the lee float, it is not necessarily a great risk to the boat either, provided it has well rounded float decks, a buoyant center hull, and an alert experienced crew.

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What About Resale Value?

A very important point to consider before purchasing any design, and the resale value of Farrier designs is the best of any multihull on the market. This is due to their excellent reputation and a high demand. Used F-27s have in many instances actually sold for more than the new price and have been an excellent investment for their owners - the lowest cost to own boat in America in fact.

The early Command 10 sailing. At 33 feet overall, the Command 10 is the largest design to ever use the Farrier Folding System - but for marina docking only, it's too wide for trailering

Are Multihulls Wet Boats?

They can be wetter than a monohull, but usually because they are going so much faster. Slow down to the same monohull speeds and you will usually be much drier. Some recent comments on this on the F-boat Forum included:

I'm a recent F-24 owner (F-24 Mk 2 #292) and am sailing on Lake Michigan. My wife and I were very much surprised how dry the boat is compared to our 33' mono! In winds, heeled over, slamming the bow into a wave always produced lots of spray, etc. into the cockpit. The F-24 seems to slam a lot less, and since it is heeled over so much less, we seem to be much dryer. Unless you're out on the nets, which can definitely be wetter, but more fun!

Mike Walters, Lake Michigan

We owned a Beneteau 235 for 12 years before buying the F-24 Mk 2. My wife loved the Beneteau - so did I. But now, we are experiencing a whole new side to sailing. Yesterday we topped out at 17.3 knots on a reach with the screacher as the kids were down below building a fort in the v-berth. Wet and roostertails are something we strive for. You can stay very dry in the cockpit - but the exhilaration is really felt on the nets!

Norm Schultz White Bear Lake, Minneapolis/St. Paul, MN.

On our F-24 Mk 2, we frequently put up the stock poptop dodger if there is any kind of weather expected (including high winds/high speed). It not only keeps the cabin open and dry, but blocks much of the bow spray and wave slap. A person can stand inside or sit in the companionway quite comfortably, see just about everything and stay dry. If you hold the boat down to monohull speeds (yawn) it is utterly dry unless a big powerboat crosses your stern and his bow wave slides up into your cockpit (mostly because you are dawdling along at monohull speeds).

Of course, the racing fanatics will point out that you are losing at least a tenth of a knot due to added windage. Whatever....

Fred Cox, Reno, NV

Why are Foils Not Used in The Floats?

Foils were tried in the prototype F-27 back in 1985. These were circular all carbon foils that could retract behind the beam, to still retain easy trailering, while avoiding the need to remove when folding or docking.

Retracted foil can just be seen behind forward beam of F-27 prototype

They worked well while reaching, but were heavy and expensive to produce, and thus their inclusion on an 'all round' production boat could not be justified.

More on Foils

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