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CAT CRAZY, TRI FI And Other Comparisons By Jim Brown

“There is nothing, absolutely nothing, quite so much worth doing as simply messing about in…” ! That paraphrased quote is pilfered for the most part from Ratty, the revered rodent in Kenneth Grahame’s venerated tale “The Wind in the Willows.” Of course, Grahame and Ratty said it of ordinary boats, and neither would have, even could have, said it of multihulls. But if Brown had been the author instead of Grahame, his character Ratty might have said something like, “There is nothing, absolutely nothing quite so creative as screwing around with multihulls.” By “screwing around,” Ratty would have spoken literally, meaning to conceive, gestate, whelp, wean and release upon the Earth’s fluid interface one’s very own flesh and blood multihulls. And that’, impatient reader, is what this appendix is about, so like most appendices reading it is strictly optional.

In that you are reading on, please be prepared for some sacrilege. Suggesting there is something divine about boat design and construction I will try to trace multihull origins by expanding on the theorem expressed by my late friend Walt Glaser who said (in Chapter 1 of my memoir, “Among the Multihulls,”), “A man builds a boat to make up for the fact that he can’t build a baby… What else can a guy produce with his own body that so closely simulates a living thing?”

It took me many years of both messing about in and screwing around with boats to apprehend this aspect of watercraft, and I admit that it still takes quite a stretch for me to accept the notion. But look at it this way:

A boat, and especially a boat, is unlike any living creature ever known. Its domain is confined to the boundary between Earth’s two great fluids, water and air. This realm is of course inhabited by many living things. There are fish that swim and birds that fly, and even birds that swim and fish that fly, but there is nothing alive that thrives on immersion in both fluids simultaneously and even takes its motive power from the relative movements of atmosphere across its interface with hydrosphere. In particular there are no beings that can work with the wind and water to proceed in a direction contrary to the movements of both.

Perhaps this peculiar void of life exists because the environment of this realm, which envelopes more than two thirds of Earth, is perverse. The velocity of the moving fluids and the amplitude of resulting perturbations in the interface can at times be extreme (to be convinced of that extremism just go to sea in a ). Nevertheless the sailing vessel – unlike any living creature – can glean an almost life-like world-girdling mobility from this environment and so enjoys free access to a wider realm of Earth than any protoplasmic thing evolved to live there. No, God never made a true sailing creature; I like to think he left that up to man. And by clinging to the backs of, or hiding in the thorax of, our sailing creatures – no matter how deviant such behavior may be – we get to go wherever they can go! Isn’t that just too totally marsupial?

So ladies, you come too. But if you find that boats are pretty much a guy thing, please consider this waterborne excuse for our machismo. Boats can make us feel, if only feel, immortal. Just thank your lucky chromosomes for the fact that you simply do not need such relatively lame creative outlets.

The Old Tradeoff…

To assure that men undertake to gestate boats, their design and construction seems purposely fraught with cosmic obstacles that are great fun for boys to work around. Principle among them is the old compromise between stability and performance. It seems this compromise pervades many facets of life: Institutions, economies, personalities, relationships... With boats – at least with single-hulled boats – great stability seems to come only at the cost of great performance. The wider one makes an independent hull the more stable it becomes but the harder it is to push through the water. Conversely, the narrower the boat the easier the stroke but the tippier the ride. If it weren’t for the enormous difference in density between water and air (a gallon of water is some six hundred times more dense than a gallon of air) there wouldn’t be much stability to a boat at all. Plowing through the water when propelled only by the wind blowing over mast and sails creates pervasive overturning forces and so requires a high level of stability in a sailing creature. Surely it has ever been so. Sailing boats have been around longer than civilization, the realm in which they operate hasn’t changed much, and the old tradeoff between gliding along and tipping over seems never fully resolved. The ancient marine architects faced the same tradeoffs as we do today, and I find it quite engaging to consider their original solutions.

My own investigations into this matter are amateur and casual, but in this quest I have been aided by my friend . James is one of the few originators of modern multihulls who relates his work directly to the achievements of ancient people.

I recently enjoyed a cruise through the Greek Islands with James and his crew aboard their 63-foot SPIRIT OF GAIA. (The term Gaia is taken from the Steven Lovelock concept of Earth as a single organism, a “living ball” wherein humanity is but one organ of the integrated smear that is the Earthly biosphere.) The captain of this grand vessel is Ms. Hanneke Boon who is co-designer in Wharram’s longstanding multihull design business. With Hanneke in complete control (James was sometimes heard to mumble, “I’m not the captain here, I’m only the Admiral”) we cruised from one idyllic anchorage to another, each surrounded by mountainous islands and crystal water. We moored off ancient towns with walled harbors and castles on the hills. James is an amateur historian of considerable depth, and as we

2 sailed a string of easy day-hops through the Ionian Sea and Gulf of Corinth he told us much about the waves of humanity that have pulsed through these islands since Etruscan times. Much of the ebb and flow of early Mediterranean empires was water-borne, but as far as is known none of it was borne by multihulls. GAIA has sailed around the world and looks like a giant twin canoe from out of Pacific antiquity but her Siamese ghost- form was completely out of context in these waters. She did, however, serve admirably as the stimulus for our discussions, even our disagreements, of sea nomads and multihull origins. Our conversations tended to mosey but they frequently return to the roles played by watercraft in the distant saga of early man.

James explained that the first cross-water movements of humanity can be postulated only from weak anthropological evidence, so a fair bit of conjecture is implied when speculating on the design of the earliest seafaring vessels and the motivation of their sailors. Very little physical evidence has survived to tell of the boats themselves, and even less is known for sure of why their creators put to sea in them.

How, James and I asked each other, did the early seafaring boats come into being? Perhaps, we agreed, the better question is why? And how far back in time did we care to take this inquiry? As our discussions progressed to PHD status (Piled Higher and Deeper) our friend Scott Brown captured something of this exchange with his video camera, and it is from that footage that the following quotes are loosely taken:

“One starting point,” James said, “might be the migration of the first Austronesian people to cross from mainland Asia to Australia. Recent evidence says this could have occurred as early as fifty thousand years ago. Common sense says these aboriginal people probably made their passages across the Torres Strait in rafts, but no one really knows what sort of craft they used or why they wanted to migrate to Australia anyway.”

“Maybe they had to move for some reason,” I said, “pushed out to sea by other people or famine or some such.”

“I think they were just nomads,” said James. "Sea nomads. And I think there were sea nomads long before there were land nomads.”

“Really! Why do you think that?”

“Simple,” he said. “The wheel was invented only six thousand years ago, and before that it was just a lot easier to move around on the planet by water than by land. After the last ice age of course there were nomadic peoples wandering on foot in Eurasia and elsewhere, but to populate the whole planet they faced not only oceans but thick forest, mountains, jungles, swamps and deserts. On foot they were lucky to make five or ten miles per day. When they came to lakes and rivers they had to have a boat anyway. Let’s say they started with rafts. Now, rafts are great if you’re just

3 going to float along downstream with the current, but to cross wide water a raft has tremendous drag. You can’t really paddle a raft, it has to be sailed and even then it is very slow going. But if you’re already into paddling and sailing, how about a ? They are vastly easier to push through the water than a raft because their hulls are narrow; their breadth is limited by the diameter of the log from which they are made. So with a narrow dugout canoe you can make twenty or thirty miles per day compared to five or ten on foot.”

“Okay, that makes sense,” I said. “And if you have a boat, at least you’re not carrying all your stuff on your back. But where does the multihull come in?”

“A multihull is nothing more than a raft made of canoes,” said James. “A canoe by itself is a wonderful thing until you get out into open water when it becomes rather tippy in the waves. The raft is far more stable. But it doesn’t take a computer to tell you that a canoe with a log float out to one side OR maybe both sides, or two canoes spaced apart but bridged together, will give you raft-like stability combined with some semblance of the easy paddling or sailing of a canoe. Those people were not stupid. They had the same Homo sapiens brain power that we have! After all, it’s a lot easier for us to explore the Greek Islands for the fun of it if we have a boat that is easily propelled, and we’re doing exactly the same thing right now as did the ancient sea nomads.”

“So I suppose they didn’t need multihulls here,” I said. These waters are protected by a sea of islands so they didn’t need raft stability but they did need to carry heavy loads. Maybe that’s why they stuck with monohulls. When they started carrying cargoes and cannon, they built their hulls from planks so they could make them wider and deeper.”

“Exactly,” said James. “And you know, Jim, I would have been happy with some sort of historic monohull. I would have been happy with a small Viking ship. I could have done with a little , a or a -type vessel. But as a young man I didn’t have the skills to build such craft. They were highly developed and complex. But as a result of Eric De Bischop’s voyages in the 1930s – you know, he was the first to sail all three oceans in a catamaran – and the studies I made of Pacific seacraft, I came to the conclusion that with a double-canoe-type vessel I could have the most boat for the least materials and just the basic skills. That’s why I ended up in .”

“It was the same with me,” I said. “I came from a rather traditional yachting background, sailing big around the Caribbean. I loved those boats, still do, but I made my way to San Francisco to work in a certain boat to learn about fiberglass. It was new then. There I was, boatless on beautiful San Francisco Bay, and I knew there was no way I could afford a big old . But I bumped into Arthur Piver, and at the time – this was the mid-fifties – he was experimenting with his first modern . I just happened to be there. So with you it was Eric de Bischop and his catamaran, and with me it was Arthur Piver and his trimaran, and

4 let’s admit it James, those early multihull trail blazers literally shaped both of our lives.”

“I think something like that was ready to happen for us anyway,” said James. “It was the culture of the times, the post war can-do generation. Anything was possible and we were ready for adventure. And I think the same thing drove the ancient sea nomads. The world was wide open for them even more than it was for us.”

James and I agreed that we needed to know more of formal anthropology but we both were tempted to conjure our own reconstruction of . I expounded, “Stone Age men didn’t just wander out into the ocean without some dire need. “They had to be driven by survival,” I contended.

But James felt that, “Like ourselves, they did it for adventure, for manliness and fun.”

“I worked in the for a while,” I said, “and their traditions tell of trouble in Asia about two millennia B.C. Hordes of starving people came down from to what is now Vietnam and overwhelmed the coastal people there. The invaders were more technical but the coastal folk had two things the invaders lacked, fish and outrigger canoes. They had knowledge of along-shore seafaring. Of course these groups intermarried and in time their numbers burgeoned and they outstripped the local environment. From what I heard about it, some factions were persecuted and literally driven out to sea where they colonized what is now The Philippines. ”

“Maybe so,” said James, “We need to know more about those population pressures, but look at the Vikings. A lot of their voyaging was done to encourage their youth to venture out into the world and become men.”

“That sounds like the young Pacific Islanders,” I agreed. “I’ve heard that in the British island colonies the youth would sometimes sail hundreds of miles on a whim just to get some cigarettes.”

“That’s what I mean by fun voyages,” said James. “And I bet they went for cigarettes in an outrigger canoe. A single-outrigger canoe. We westerners tend to think of the main Pacific vessel type as the twin canoe or catamaran, but when you look into it you learn that most of the early Pacific voyaging was done in single outriggers.”

“They still predominate,” I said. “There are hundreds of thousands of single outrigger canoes in use in the Pacific Islands today, especially in the Gilbert Islands, or what is now called the nation of Kiribati. Those are Micronesian people and they have beautiful canoes. They’re the local equivalent of our family cars.”

“Of course, that’s literally the only way to get around an archipelago without some kind of petro power,” said James.

5 Although,” I said, “it’s hard to find a greater concentration of indigenous multihulls than in the Philippines, where the native craft are almost all double outriggers or what we would call . They call them bancas, and when I was there in the eighties the official government estimate of the number of bancas in use was seven hundred thousand! That’s a lot of trimarans!”

“Amazing,” said James.

“That’s how those islands were populated,” I said, “by trimaran. It’s not far from Vietnam out to the Philippines, and their oral history says they came in giant double outriggers. So I think the first seagoing multihulls were trimarans. But it didn’t take long – maybe a couple of hundred generations or so – for the Philippines to become over populated. From what I’ve read of anthropology, and that’s not much, the early Philippinos were again pushed out to sea by population pressures, only now they were looking right into the prevailing wind and right at the wide open Pacific.”

“You may be right but I think we need to know more about the demographics of the time. Were they really being driven out to sea or were they just adventurous nomads?”

“Well, the story goes that they knew there was more land out there because stuff kept floating in – coconuts, logs and land animals – and yet they had to go to windward to look for the land. And I think that’s where the single outrigger or came in. This is just conjecture James, but it seems logical to me that the trouble with their double-outrigger bancas was that the downwind float kept getting ripped off by the waves. We can see in modern trimarans that the downwind float takes a lot of thrashing, punching right through the crests. We can hold them together today but the Ancients didn’t have our materials. Their boats were real lashups, all tied together with string made from coconut fiber. Within their huge archipelago they were always sailing in protected waters and balmy breezes, but to continue eastward into the open Pacific they needed a real sea boat. So just imagine the sequence now. A bunch of boys sail their banca trimaran from one island to another on a reach, and on the way their downwind outrigger gets torn off. So they just hike out to windward on the other float and keep on to the island. But how are they going to get back? For the return trip the one outrigger float they have left would be on the downwind side! So instead of risking the loss of their last float they shift the mast and sail to the other end of their canoe and sail home stern first. Presto! The shunting proa. It sails either end first to always keep its single outrigger float on the upwind side. And after suitable development, that turns out to be the vessel of choice for exploring the entire Pacific. The proa is the most prevalent of the indigenous multihull configurations still in use today, yet we know little of it in the west.

James laughed and said, “That’s quite a theory, but how do you account for the catamaran?”

6 “It came a little later. First there was the double outrigger or trimaran, the original vessel of along-shore fishing and migration to island Asia. Then came the single- outrigger, shunting proa, the first real seafaring vessel that could go to windward in the open sea. So it became the vehicle of choice for exploration. And last but not least came the twin-canoe or catamaran, and it was the freighter, the vessel of choice for colonization. It could carry extended families, little kids, pregnant mothers, aging chiefs and everything, all their flora and fauna for survival in a new land. Because they already knew where they were going they could make long voyages to colonize places like Hawaii and Easter Island and New Zealand.”

“Well Jim, that also explains why the catamaran is still the roomiest and best load- carrying multihull configuration today.”

“Come now!” I said. “We haven’t really talked about modern trimarans.”

“No, but we were speaking of ancient times, and your theory is all very well but I think things were not all that cut-and-dried. I expect the early sea nomads used all types of vessels and all pretty much at the same time. And furthermore, in our time the catamaran came first, then the trimaran and then the proa. So how do you account for that?”

“Well, it’s because men like Eric de Bishop and Nathaniel Herreshof and Woody Brown and Rudy Choy and even that James whatshisname were all attracted to catamarans and I still don’t understand why (background laughter). And you guys put to sea in them in the nineteen fifties before men like Arthur Piver and Norman Cross and Ed Horstman and Lock Crowther – and even that Searunner dude – Brown is it? (more laughs) – Came along to popularize the trimaran. But nobody did much with a modern proa until Dick Newick showed up in the seventies with his so called ‘Atlantic proas,’ which the ancient Pacific people would have said had their outriggers on the wrong side. (More background laughter.) But I think the proa has a lot to show us yet in modern times.” James and Hanneke have since made an epic voyage in a single-outrigger canoe. See http://amazingdata.com/4000-miles-down- the-lapita-pottery-trail/)

By the end of our cruise in GAIA James and I had convinced each other that both motives for the ancient voyages, survival and fun, must have been at play. And we agreed that all three multihull types still have a lot in store for modern humankind.

Perhaps to avoid real disagreement, James Wharram and I never discussed the differences between the modern catamaran, trimaran and proa. Below I’ll offer my own thoughts on this matter, and to balance comment we must hope that James proceeds with writing his own book. Meanwhile, I wish fair winds for the great ship SPIRIT OF GAIA and all who sail in her.

7 Bogus Biology…

In this comparison of modern multihull creatures, the catamaran and trimaran are like apples and oranges, and the proa is maybe a kumquat. All are so incomparable that they sustain mixed metaphors, but the proa especially is mutant (as discussed in Chapter 17). Actually, all three types are of different “species.” They are not fruits, they are fauna, and I put them in the genus vaka. (This is my term to genetically classify all multihulls. The term Vaka and its many variations like banca are widely used today in the Pacific to mean outrigger canoe. They all descend from wangka´, which is the earliest known Austronesian word for boat.) In this bogus biology, then, the general phylum is boat, the multihull genus is vaka, and the known species are catamaran, trimaran and proa. However, many multihullists consider the only creatures in the whole phylum are catamarans. To them trimarans are all together something else – not multihulls at all – and they’ve never heard of proas. To those poor lubbers the following comparisons will be moot. Furthermore the writer of this is definitely a trimaran devotee. I am “faithful” to them just as traditional sailors feel some level of fidelity to monohulls. I call it Tri Fi, and what follows is a face off between Trimaran Fidelity and its counterpart called (unfairly) Cat Crazy.

Multihull Structures…

The catamaran would appear to be the simplest of multihulls. It has two usually- identical hulls connected by a single bridge to produce enormous initial stability. Conversely the trimaran has an extra, larger hull of different shape in the middle with a bridge reaching out from both sides to grasp relatively smaller stabilizing “float” hulls. In the early days of modern multihulls it seemed to me that mounting cross beams in the central hull of a trimaran and then attaching float hulls to those beams was easy. At least it seemed structurally easier than joining two big catamaran hulls together wide apart. Further apparent disadvantages to the catamaran were that it had no obvious place to step the mast or attach the headstay, and it still pretty much requires two , two centerboards or keels and deserves two engines. Nowadays, however, the structural challenges of both types are well resolved by most designers, and it seems they each have their share of complications and duplications, so where do the two really differ?

They differ profoundly, I believe, in matters of accommodation, riding motion, safety and intuitiveness. These matters do not resolve in a washout but instead in a new kind of tradeoff. Prospective multihull buyers usually express three main desires for inclusion in their boat: Vast accommodation, high sailing performance, and low cost. Please note, however, that Dick Newick’s famous axiom states that of these three only two – any two – are achievable in the same boat. To that I would like to add that in multihulls you can have any two of three additional properties: The privacy of truly isolated living spaces, a very smooth ride in very rough water, and a high level of

8 ultimate safety. Again, only two of the latter three are achieved in the same multihull. Let me explain:

Most of today’s seafaring cats offer three separate spaces in which the crew can live, the bridge deck cabin and the two hulls. In today’s very popular charter cats most of the cooking, eating and socializing are done in the bridge cabin, and the bathing, intimating and sleeping are done in the two separate hulls where the privacy of one is completely separated from the other by the bridge itself. For term chartering and living aboard with family this is an unbeatable combination, and it explains a lot about why the boating world has gone cat crazy. Most people want their boat to be as much like their shoreside home as possible, and the modern catamaran comes closer to being a condo than the other multihull types.

The trimaran’s interior sometimes appeals more to people coming out of monohulls, wherein one can put his feet down below the waterline and in the middle of the boat. This is in stark contrast to the cat where one’s standing level in the central bridge is high above the waterline although often not high enough (more on this is coming). In most trimarans the living space is all-in-one, with the bunks and the bathing contiguous with and connected to the cooking and the navigating areas. Some trimarans achieve a fair semblance of privacy by relegating the cabins toward both ends of the main hull, and these cabins are separated by a central cockpit, but this is still not as effective as locating, say, the kids in one hull of the cat and the parents in the other with the ”living room” between. (In sailortalk, the living room is referred to as the saloon.)

Nowhere is this separation-for –privacy more complete than in James Wharram’s SPIRIT OF GAIA where there are eight private, double cabins surrounding the central open deck area. As Hanneke Boon explained, “This boat is like a village, with all the private dwellings opening onto the town square.” Of course the “square” has no shelter, (an open-air saloon?) which has its consequences in foul weather, but I have found the “village life style” of that boat to be unexpectedly appealing. It took some getting used to and is certainly not for everyone, but I now understand its origins in James Wharram’s concept of modern cruising as an extension of yesteryear’s “sea nomads.” At least the Wharram solution of the uncovered catamaran bridge is free of what is seen in most cruising cats, those horrendous bridge-cabins. Jo Hudson calls it “the school bus effect.” So here it comes now:

The New Tradeoff…

Instead of compromising between performance and stability, as with monohulls, the main multihull tradeoff is between tunnel space and top hamper. In the trimaran’s main hull one stands erect with his feet well below the waterline with standing headroom in a superstructure that shows only modestly above the vessel’s deck. In the catamaran’s bridge cabin, however, one stands with his feet well above the

9 waterline… The higher the better! To achieve headroom in the cat’s saloon, the superstructure – no matter how disguised by spacey styling – must protrude skyward like those goony-looking wind deflectors set atop today’s semi-truck tractors. Indeed, to my eye, most cat cabins seem to plead for the semi’s gleaming, shielded, twin exhausts that stream blue soot into the wind.

Sailortalk can be quite expressive. Excessive elevation of the superstructure is aptly called “top hamper,” (hampered by its top) but I admit that this tradeoff in cats is mostly a matter of aesthetics, a slap in the eye of the uninitiated beholder. Of course excessive elevation does “hamper” the progress and aggravate the motion of any watercraft, but that’s not the real issue here. The real Achilles heel of multihulls is the amount of space in the tunnel between their hulls, their “underwing clearance.” The underwing panel of the bridge-cabin catamaran is a very large surface that belongs in the air but invites pounding by the water. We’re not talking slaps here, these are slams, and these slams occur right under the floor (called the sole in sailortalk) of the bridge cabin. In rough going the cat’s hulls can also be very noisy, sometimes to the point where the off watch is driven to try sleeping on the sole in the bridge. Diabolically, I have seen six prone guys trying to sleep on a cat’s bridge sole all bounced airborne by a single slam to the underwing. “No rest for the wicked,” one groaned.

And another said, “If only the designer was among us.”

But it’s not all the designer’s fault. It is also pressure from the public, from the uninitiated, prospective boat buyer, that induces catamaran designers to lower the underwing, this in an effort to produce a smallish cruising cat that has a voluminous bridge cabin with standing headroom while trying in vain to lower the school bus. There are a host of such “roomarans” on the market, and most buyers of these craft would not consider taking them to sea, which is fine. These boats serve admirably as a mobile cabin in the pines.

For those who intend to cruise blue water, however, I suggest the following procedure for selecting your catamaran: Walk down the dock at the boat show to a position between the sterns of your subject and lie down prone on the dock. Never mind what bystanders think or say. Now, with your eyes as close to the water as possible, look under the wing of the catamaran in question. Could you pass between the hulls and beneath all parts of the underwing in a kayak? In some cats you can’t even swim through the tunnel without a snorkel, but if you’re not sure, borrow a kayak and try. You can duck your head and bend your waist, but if you can’t pass through all the way, don’t buy that boat for seafaring. The salesman who has a suitable product can make hay by providing the kayak, but those who wouldn’t dare will tell you, “No sir, this catamaran has sailed across the North Atlantic without ever pounding its bridge deck.”

To that you may respond with Dick Newick’s favorite expletive, “Oh ballast!”

10 Of course the bigger the boat the higher the underwing clearance must be. This is especially true in the large, very modern cats which are extremely wide for their length. Such vessels are wide enough to straddle wave crests, which can give them a real whacking on their Achilles heel. The phenomenon is further aggravated by overloading the boats (cruising boats are notoriously overloaded) and by narrow hull forms with more-or-less vertical topsides (that’s the above-water sides of the hulls). This leads us into a discussion of riding motion:

Over The Bounding Main…

Let’s begin by mentioning all six axes on which a boat moves: There are the usual modes of roll, pitch and yaw, which almost anyone can visualize. But then there are the other three: surge, sway and heave. Surge is the tendency for boats, especially sailing boats, to proceed in spurts of acceleration and deceleration. Sway is the boats purely lateral nudging left and right as it sails across the reversing currents within waves. And heave, the most obscure motion of all, is a boat’s propensity to bound up and down vertically like a spar buoy bobbing in a swell. This is not “hobby horsing” or “rocking chairing,” though that pitch is often combined with heave.

Heave is a purely vertical, “bouncing” motion that is seldom recognized because it is often obscured when motion on all the other axes is happening at the same time. But heave relates directly to pounding on the underwing; if a multihull heaves in a seaway, of course its underwing becomes somewhat closer to the crests at the bottom of its bounce, and this invites it to pound as the vessel’s underwing is literally dropped on top of the waves. This aspect of pounding is prevalent in racy boats that are used in the charter trade and therefore often heavily loaded with passengers. Their narrow hulls with vertical topsides (little or no “flare” above their waterlines) are prone to heaving and pounding when loaded. Generally speaking, a lack of flare (getting wider above the load waterline) means minimal “reserve buoyancy” to resist the deeper immersion caused by both loading and heaving. Such lean hull forms are, in my opinion, inconsistent with chartering and cruising, for such craft are so often overloaded.

Pounding on the underwing is not just an issue of quiet and comfort. Besides the common structural damage done by pounding, the resistance of a multihull to passage through the water (especially at the lower speeds when close hauled to windward) is largely a function of its wetted surface. Multihulls have more wet surface than monohulls even when lying at rest, and when pushing over waves they expose all their multiple topsides and their entire underwing to the waves, thereby increasing wet surface drag astronomically. This is especially true in boats having exposed, vertical faces on their transverse cross beams underneath the wing. I have seen a big cat go from fifteen knots to a dead stop when one wave immersed the entire underwing all at once. It was like running into a rubber wall; my weight was thrown against the helm to bend the wheel, and one crew in his bunk suffered a

11 sprained neck. This was an extreme case, racing hard in a sixty footer having notoriously low underwing clearance, but it was very illustrative of the underwing wet surface problem. Again, low underwings result in part from client pressure on designers to achieve both a voluminous interior and a low aesthetic profile, particularly in catamarans. So lie down on the dock and climb into that kayak, and tell your designer you will not tolerate a lot of pounding at sea.

Not that trimarans don’t pound. As Walt Glaser used to say, “Trimarans don’t pound except in pounding conditions.” It’s just that their underwings are usually higher (because they don’t have standing headroom over them) and their underwing surfaces are smaller; they are divided by the main hull into two sections and the upwind section gets higher as the boat heels. Yes, the downwind section gets lower with heeling and can pound annoyingly, but nothing like in a cat. (In the tri, most wave crests slam outboard near the floats and therefore well away from the main hull’s living space.) Trimarans are relatively wider than cats but again their width is divided by the main hull to produce narrower spaces between the hulls, and this results in yet another subtle motion comparison between cats and tris:

Most of a boat’s violent motion occurs when the craft is making its way against or across the wind and waves. Monohulls can deal with waves one hull at a time, but in multihulls there is a time difference between when one hull and then another hull deals with the same wave. Because of the wider hull spacing in the cat, this time difference is of relatively longer duration in cats than in tris, and as I understand it, this time difference is responsible for the generality that trimarans have a smoother riding motion than catamarans. This is indeed a generality, but it seems to hold water. To illustrate, let’s consider the two types when close hauled to windward:

The waves are approaching diagonally on the catamaran’s windward bow. That bow encounters a crest and rises to it but the downwind hull has not yet encountered the wave to the same extent, and so (by exerting great torsion loads on the connecting bridge) the downwind hull restrains to some extent the upwind hull from fully rising to the crest. Now the downwind bow encounters the wave and both bows, being of equal size and shape, rise upwards together for an extended period of time.

Now the crest passes beneath the middle of the upwind hull, which tries to drop down over the back of the wave… But the downwind bow is still trying to climb the crest. Again by exerting great torsion stress through the bridge, the downwind hull tries to prevent the upwind hull from dropping over the wave until…

The crest now passes beneath the middle of the downwind hull and the same time difference applies under the sterns. The upwind stern gets booted upwards by the crest but the downwind stern is not yet ready to rise. When the crest reaches it, the whole boat is given a prolonged kick under its two afterbodies that slams both bows down onto the back of the wave.

12 Okay okay! Don’t shoot. The above is a brutal affront to my many catamaran friends, and actually I love cats, especially big ones. I am proud of the big ones I have designed, and I know the type has earned its dominant position in the multihull marketplace for good reasons. But please allow me to continue their comparison with trimarans;

As the wave approaches the trimaran’s weather bow diagonally, the whole weather hull is flying clear of the surface, or at least it should be if the breeze is up and the boat is not grossly overloaded. The sharpest crests may slap the outboard bow and send spray flying, but normally the waves don’t reach the weather hull of a close- hauled trimaran. So now the main hull begins to rise to the crest. The hull spacing distance (and therefore the time difference) to the downwind float is less than in an equivalent catamaran and that float hull is somewhat narrower and has much finer ends than the hulls of a catamaran. Therefore the torsion stress in the downwind bridge can easily tell its float bow to start to rise with the main hull. Nevertheless, that float hull is being seriously pressed down by heeling effort from the sails, so as the main hull begins to drop down over the back of the wave, the float bow is often driven right through the crest; it does not have to climb over! This is normal trimaran deportment, and in fact is desirable because the floats do not talk back stridently to the main hull. Instead the main hull is free to respond to the wave more or less like a monohull. Once the wave passes under the stern of the main hull and encounters the somewhat shorter, finer and shallower downwind float stern, it finds there’s not much to kick in the butt as it passes into the wake. The trimaran, therefore, is nominally steadier in pitch than the catamaran. Trimarans heel more than cats, but because of the smaller outboard floats their roll motion is generally softer, less snappy than in cats.

The difference may be small as felt on deck and in the hulls but it is more severe higher up. Cats with high bridge cabins normally require the helmsman’s chair to be very high in order for the helmsman to see over the school bus, and in some conditions this height causes the pilot to experience significant fore and aft surging in that seat. (Its rather like the old motorcycles that had suspended saddles but no rear shocks; their seat and handlebars jerked front-to-back on rough roads.)

This whipping fore-and-aft is nowhere more punishing than in the sails, where their alternating luffing forward through the wind and hauling back overtrimmed actually prevents the flow of air over the fabric foils from becoming steady and attached, thereby depriving the craft of power. This may explain why the trimarans win a majority of the upwind races, while it seems that cats can be driven harder off the wind.

Cats and tris also differ in their use of centerboards and rudders. Rudy Choy used to say, “Two rudders are better than one.” Indeed for downwind control in surfing conditions, the twin rudders of the cat are thought to be better than just one in the tri. Unless, that is, that trimaran is fitted with a skeg-type or a more powerful, deeper-than-the-hull blade that can kick up when striking obstructions. Kick up

13 rudders are mounted on the transom and so can be easily un-shipped for maintenance or repair even at sea, so of course, catamarans can also benefit from deep, kick-up rudders. Cats require some kind of dual steering linkage between the two rudders and the single helm, and this can be complex compared to the single linkage in the trimaran. For kick-up rudders, the linkage must be arranged to allow steering the boat when the blade is kicked part way up and dragging the bottom.

Swing-type centerboards that retract automatically upon striking obstructions are indicated for cruising multihulls. Vertically retracting “dagger boards” have been responsible for tearing out the bottoms of too many multihulls; in my view they have no place in a cruising boat. Whichever type is used, catamarans pretty much require two. Either type starts downward from a deeper hull in trimarans than in catamarans and so can reach down deeper into solid, quiet water and hang on. Also, a single centerboard located in the main hull of a tri – underneath the mast and sails – seems to improve steering and maneuvering. In any case, both centerboards and are heavy, costly and troublesome, but you get something for them: You get substantially superior windward performance, tacking ability and downwind steering properties.

The shallow, fixed keels used on many multihulls are a reasonable compromise. They serve well to protect the hulls when grounding and hauling out, and they protect fixed rudders and inboard propellers. While low-aspect keels cannot provide the same level of windward performance as vertical foils with “aspect” (deeper than they are wide), they are acceptable in boats having good inboard power. Outboard – powered multihulls become pure in rough weather when their surface- piercing drives become useless. In my view, outboard auxiliary power is justifiable mainly in craft with real centerboards or daggerboards so that they can really drive upwind against breaking seas under sail alone. Deep fixed keels negate the principle multihull advantage of shoal draft. Finally, the deep, on-center foils of a trimaran seem to dampen riding motion in both yaw and roll.

To complete this admittedly biased treatment of the differences in riding motion between tris and cats, please consider the very wide variety of hull forms used in trimaran floats. The usual deep V float sections of the early days had advantages but were found too soft or squishy in preventing roll. The ensuing chined sections or “bulging V” floats had more buoyancy down deep and achieved a good compromise but are now considered to have too much wet surface for high performance. The resulting rounded section – almost flat bottomed – floats seen in today’s racing trimarans are definitely faster, but in some conditions they can pound and snap the boat laterally. The “snap roll” of multihulls is an endemic trait of them all when sailing in beam seas or confused chop, and in my opinion is aggravated beyond acceptability by giving trimarans extremely full-bodied floats. They might work for racing but they have no place in a cruising trimaran. However, unless a trimaran has very full-bodied floats, trimarans heel more than cats. If sailing flat is your priority, choose a catamaran, but note that the snap roll of today’s wider cats can also be severe at times.

14 Finally, catamarans are better on the hard and on the beach than trimarans. When beached in a surf, the cat will sit there like a sled while the trimaran reels drunkenly from float to float in the swash, pivoting on its deeper main hull that is aground. This rolling may, however, be helpful when kedging the trimaran back into deeper water, but if you intend to do a lot of beaching, choose a catamaran.

Zero Hour…

Of course, the more comfortable the crew the safer the trip, but let’s speak of ultimate safety, Like when upside down. As discussed at length in my 1981 book “The Case For The Cruising Trimaran,” we have learned the hard way that the prospect of capsize in multihulls is about as likely as the prospect of sinking in a monohull. Both are mercifully rare, but we have also learned that the aftermath of capsize is much preferred to the aftermath of sinking. Furthermore, all aftermaths are not created equal, and here again the trimaran has I think a significant advantage. Assuming that neither type is more likely to flip than the other, and that both types are more stable upside down than right side up, what can be the difference?

The answer is in the trimaran’s superior inhabitability when inverted offshore. A hatch can be installed or cut in the trimaran’s main hull’s bottom to provide air and access for the castaway crew living inside, but the catamaran’s crew is normally forced to take to a life raft. Why? Because the catamaran’s “escape hatches” will violate the air lock in its hulls and allow the craft to settle too deep to inhabit, whereas the trimaran’s outrigger hulls can retain their inverted air lock. This floats the main hull high enough to provide shelter and supplies for the castaway crew, a situation far preferred to surviving in a life raft.

A lot more has been said about capsize survival by myself and others, but not enough about capsize preparation and prevention. Briefly, all offshore multihulls should be equipped with what Phil Weld called his “Calamity Pack.” Tools, water, food, EPIRB, and hand-held VHF radio and satellite phone will set your mind at ease and allow you to enjoy your trip knowing that there is some alternative ready should zero hour approach.

For cruisers, capsize prevention is easy; just stay out of the wrong piece of ocean at the wrong time of year. By playing the predictable ocean wind patterns you can sail around the world many times without running into survival weather. And of course you can always slow down to hold a big chunk of your performance potential in reserve. The resulting safety margin of this tactic alone will justify the multihull in any discussion of safety.

15 For racers? Well, let’s face it: By sailing without reserve you guys ask for capsize. In order to win these days you have to proceed at flank speed even in threatening conditions, and the singlehanders among you must do this often with no one on watch. What can you expect? Rescue? In my view you have no right to expect the costly and dangerous rescues you often receive. Yes, this is only my own position, and maybe I’m just too chicken to enjoy racing offshore. I see a parallel between the frequent breakdowns of all the “modern inconveniences” so evident in many of today’s cruising multihulls and all the unnecessary risks implied by big time offshore racing. For myself, I feel that neither approach offers enough enhancement to the sailing experience to make them worth assuming. Fortunately, Poseidon seems to offer each of us our preferences.

Talking Boats…

It is in communication where our last cat-tri comparison occurs. When driven hard, trimarans talk to you more clearly than cats. They face you when speaking, they enunciate loudly, and they slap you in the face with seawater if you don’t listen… All before capsizing. Their language comes from the downwind float which, because it is smaller than the downwind hull of a cat, can drive right through the crests. In cruising tris at least, the floats are designed to be depressed clear out of sight before the main hull is lifted from the water. Long before that the boat is obviously heeling far too much. And the lee float is really kicking up a fuss. Consequently, that downwind float lets the crew know loud and clear that the boat is being over-driven.

On the other hand, the downwind hull of the catamaran, is big enough to support the weight of the entire boat when the whole thing is stood on edge. It doesn’t drive clean through the crests. It just doggedly streaks through the water without complaining even though the windward hull may be flying and the craft is on the ragged edge of a sudden, unannounced capsize.

I like a boat that talks to me, I like to talk to boats, and I’ve had some very chummy conversations with cats, especially the big ones. I think catamarans come into their own at about fifty feet, where the bridge cabin can have standing headroom without lowering the underwing too low… Sixty feet is better yet. They just don’t heel! They can bash through a tradewind seaway while you walk around the deck with your hands in your pockets. They’re the vehicle of choice for day-charter “cattlemaran” service and – in the hands of experienced sailors – they make great cruisers, and when one learns their language they, too, can be expressive.

The demands for high performance and big cabins have made both types astronomically expensive today. But with a smaller trimaran you can avoid the school bussing and the rocking chairing and the snap rolling and the underwing slamming with enough money left to actually go cruising! So, for a mid-size or compact ocean cruiser I’ll take a trimaran please.

16 Actually, I have one, have had her for thirty eight years. She’s an oldie-but-goodie woodie, and that brings up the issue of what material and what construction method best suits the modern multihull. It’s a controversial subject fraught with personal preferences, so let’s admit that many of these choices are not necessarily objective. They are emotional and cultural, and they are all part of the new tradeoff.

The Right Stuff…

I’m about to prove myself a fossil here: I like wooden boats, especially wooden multihulls. When I was a little kid, maybe three or four, I remember very clearly, almost as if it were today, asking my mother, “Mommy, where does wood come from?” (I had found my father’s pocket knife and been secretly whittling on the cellar stairs.) Unlike so many kid questions, such as why can’t a cow have kittens, this was one of those few that could be answered straight, so my mother looked at me and smiled and said with relief, “trees!” whango! I felt the big die of fate come smacking down on my whole self, forging my life irreversibly, and I’ve been a whittler of wood ever since.

But as with all materials wood has to be done right. My old SCRIMSHAW was done wrong. She was built without cover in a rain forest. Her economy materials included exterior-grade plywood, water-mix glue, galvanized fasteners and polyester resin for the fiberglass job. She’s been used a lot, banged around and damaged but promptly repaired, and always well ventilated and cared for. As far as I know there’s not a spot of rot in her. At thirty eight years old she looks good if not yachty, and she’s ready to go anywhere. I could not ask more from any material.

Modern wood/epoxy composite boatbuilding is a prime example of humankind trying hard to learn how to use wood efficiently. With the dangerously dwindling resource of noble wood worldwide, this comes down to disassembling the log in the least wasteful way and putting it back together in a sophisticated structure that will really last. In the tree, wood is always wet but when we saw it open it is subjected for the first time to cycles of wetting and drying. It is such a vascular stuff, so willing and able to soak up water, to swell and shrink with variations in its moisture content, that if left to the vulgarities of nature it is either consumed by fungus and bacteria or it literally tears itself apart by repeatedly changing its dimensions. However, when frozen in a glacier or buried in a desert tomb, wood is known to last for thousands of years because its moisture content has been stable. Today, lamination is the key, for it permits the use of less-than-perfect, renewable resource wood, and no matter what the structure, we must stabilize the moisture content and exclude the agents of decay.

Nowadays wooden boats are very often built with epoxy, which adds appreciably to their cost. It also adds to their strength, stiffness and longevity if it’s used properly.

17 You can’t use epoxy piecemeal. It wants to be used for everything everywhere, gluing, filling, coating and fiberglassing. Every single snippet of wood in the structure must be absolutely mummified with at least two coats (three is better) of quality epoxy resin or a goodly membrane of fiberglass saturated with epoxy. (For marine service in all climates, all exterior surfaces absolutely must be fiberglassed, and all exterior seams in the plywood must be taped with extra layers of fiberglass). If this work is done with care and skill it is not absolutely necessary to use marine grade plywood everywhere; and a boat built this way – if not neglected – can last for generations. This is nothing new; a 1980s survey of New England boat yards revealed that their operators believed the construction method requiring the least maintenance of all was “cold molded” wood. I contend that rating applies to any laminated wood/epoxy composite construction that is done right.

One way to do it right is to do it yourself, and I believe the material of choice for owner-builders of cruising multihulls is still wood. If you want to build your baby to “come alive” for you, consider building it of something that has lived. We all learned in grade school that the leaves of trees absorb carbon dioxide and produce oxygen and engage with sunlight and chlorophyll in some magical process called photosynthesis to produce a sugary juice that “feeds” the tree. But when we looked at a tree, all we saw was something rooted, static.

Actually there’s a whole lot going on in a tree. For example, wood doesn’t grow on trees, trees grow on wood. The only part of the tree that is truly alive is a microscopically thin layer of cells right under the bark (sometimes it reveals itself as a single layer of wet Kleenex™). The cells in this cambium layer contain protoplasm and are capable of dividing to produce more cells. During the growing season they divide rapidly, expanding outward by literally burying their forbears in the log. It is these ancestor cells that, after passing through stages known as the xylem and phloem and becoming hardened and toughened by something called lignin, develop into wood.

Another thing happening in trees is their co-axial, slow motion, upside-down waterfall. Using capillary action, a certain layer of cells within the tree carry water, sometimes hundreds of gallons per day, all the way from the ground to the leaves, sometimes hundreds of feet up. Almost all of this water evaporates to cool the leaves and keep them from getting fried by the sun. But a little of this water becomes the carbohydrate juice produced by the leaves that is carried back down – by another layer of cells – to nourish the multiplying layer that is alive. These two layers of cells are located co-axially, one inside the other, and their fluids travel in opposite directions.

Something they never told me in school is that wood is the physical foundation of life, the actual underpinning for the most elemental manifestation of all living processes. The trunk of a tree is evolved over eons to support the considerable burden of displaying leaves to sunlight, sometimes tons of leaves or needles, and the resulting photosynthesis did much to create our breathable atmosphere.

18 Moreover, the environment in which wood supports that display of leaves is as perverse as the surface of the sea. It features sun, rain, ice and especially wind. Consequently the wood fiber has become extremely stiff and resistant to fatigue. When used in composite with epoxy it reveals amazing engineering properties, almost as amazing as certain man-made fibers such as graphite and glass. Yet it is much more workable than those. Wood has thickness and therefore stiffness, without getting heavy and without the need of cores and skins, all at a fraction of the cost.

What cores? What skins? Well, there are several alternatives to wooden boatbuilding, but principle among them today is some form of foam/fiber sandwich construction. That is, a sandwich filling of some flimsy (relative to wood) chemical foam is sandwiched between crusts of resin-saturated, synthetic-fiber fabric. While that method can produce a splendid custom boat, and is the common choice for production builders because of its repeatability when used in a mold, I personally think most foam/fiber methods are unacceptably tedious, complex and costly for one-off custom building, especially by the owner builder. First of all the materials are dreadfully expensive. In today’s petro-economy the price of a board foot of polyurethane foam is about ten times the price of a board foot of wood. Moreover, to achieve confident bonds between the fiber skins and the foam core, everything has to be vacuum bagged, and worst of all, the entire surface, inside and out, must be skinned and bagged on both sides! Even more demanding, unless produced in a polished female mold the cored method usually produces a rather rumpled surface that needs a complete smothering in epoxy fillers followed by ages of sanding, re- filling and sanding again and again. The builder’s exposure to potentially toxic dusts and vapors is higher than with wood, and the costs in expendable bagging materials, abrasives and the builders youth are in my opinion totally unacceptable for all but well sponsored racing syndicates and deep-pocketed people. Furthermore, when done improperly or when damaged, foam/skin can be insidiously hard to repair. Both impact and fatigue can cause the skins to delaminate from the core or the core itself to become spongy. Cores degraded by cyclic stress often go undetected. Once the stuff starts to delaminate the extent of that delaminating is often a great guess to determine. When water gets into the laminate the extent of the incursion is difficult to determine. Conversely, smashed or rotten wood is relatively easy to detect and replace.

Foam/fiber can make a lighter, stiffer and potentially faster multihull but not necessarily stronger and more long lived or more beautiful relative to wood. A varnished wood interior can be very welcoming compared to the drywall-like, “frozen snot” starkness of fiberglassed living surfaces, and plastic (especially when all painted hospital white) simply cannot approach the aesthetic feel, sound and look of a well built wooden boat. I think wood is the right stuff of which to build your baby even if you don’t build her yourself, because no matter where your obstetric adventure may take you, at least your offspring is made of something you can love.

19 See! I really am a fossil, a multihull traditionalist. But if age-old heritage is any indication of tradition, then multihulls are the most traditional seafaring vessels of all. The way things are going, however, I think it’s time to remind the multihull community that tradition in boats implies beauty. The modern racing multihulls, especially the new trimarans, appear stunningly beautiful to me, and their images will likely survive through time as artful icons of the past. But certain production multihulls suggest they are the pontoon-ed progeny of Dove™ soap mothers on thalidomide as sired by a UFO. Is this what marketing men are pushing on the public? Or is the public demanding it? If it’s the latter, then let it be publicly known that the essence of a boat is vehicular. Understandably, some landspeople think of them as domiciles.

Oh well, that’s why they make both chocolate and vanilla. Mercifully the cosmic interface between atmosphere and hydrosphere usually permits Ratty and the rest of us to keep on “messing about” in multihulls of whatever type – despite their tradeoffs -- old and new – that we can learn to love.

Books by Jim Brown:

Case for the Among the Multihulls Among the Multihulls Cruising Trimaran Volume One Volume Two

And Audios…

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