What is an Atlantic Catamaran?

An Atlantic Catamaran(tm) is distinguished by a center sailing cockpit, aft pilothouse arrangement. In the early 1980s all of the available cruising catamaran designs required that the helmsman be positioned on the aft deck behind the deckhouse. From there visibility forward and to the sides is impaired, and access to the mast to raise and lower sails is difficult. With the development of the Atlantic Cats, Chris White improved the safety and utility of the cruising cat by “reversing” the normal configuration. With the cockpit forward of the deckhouse, the crew has complete forward visibility as well as easy and safe access to all sailing controls. Another clear benefit is that the deckhouse was transformed from the normal catamaran “living room” into a beautiful and comfortable pilothouse where the boat can be safely navigated and steered.

How long have they been around?

Chris White designed the first Atlantic Catamaran(tm) in 1983. At the time, the concept of placing the cockpit forward of the deckhouse was unknown and untried. The original Atlantic 50, Arabella, is still sailing, having logged over 75,000 thousand miles as both a cruising yacht and a day charter workhorse. Later Atlantic cat designs evolved from the concepts pioneered in the Atlantic 50, with refinement of the design, materials and methods into the Atlantic Catamarans that exist today.

For those interested, the design sequence is:

Is the Atlantic Catamaran concept patented?

Even if a patent had been applied for and awarded it would now be expired as protection is good for only 17 years.

It took a long time but the imitators have arrived and there are now several cats being sold with Atlantic Cat inspired forward cockpits. Even Lagoon jumped into the act with a vestigial “cockpit” near the mast in one of their designs. As the saying goes however, “copies are seldom improvements”. I have yet to see any other design that offers the safety and versatility of the Atlantic Cat configuration.

Atlantic Catamaran is a trademark of Christopher R. White and is used to identify the catamarans in this design series.

How much do they cost?

I search the world for builders who can produce top quality boats at a reasonable price. The major cost variable is labor, as the cost of materials is basically the same everywhere. In a low labor cost environment the bill for materials can be over 60% of the total construction cost. But the labor rate in a given location has to be viewed in the context of the labor efficiency. One man/hour in a good shop in the USA or New Zealand is often the equivalent to two or even three man hours in other countries. And it takes a HUGE number of man hours to build a good cruising catamaran

Don't confuse costs and quality. There are many very expensive boats built to very low quality standards. And there are a few excellent high quality boats built at low cost. It is all in the details and that takes good design and careful management in the boat shop.

All that said, a custom or semi-custom built Atlantic Cat will often cost about the same as a similar size offering from the mainstream catamaran boat builders such as Jenneau, Catana, etc. In some cases the Atlantic Cat has actually been less expensive even though it uses far superior materials in construction such as epoxy resin, SAN foam, carbon fiber, and much closer attention to weight control.

What is equally important to the boat buyer is the value of the boat when it comes time to sell it in five, ten or twenty years . The sales history of used Atlantic Cats is excellent. While there are variations due to the age, condition and location of the boat, for the most part resale prices remain remarkably stable over time and trend higher with inflation. This only works when a boat holds up well, and the Atlantic Cats do. I was recently involved in the sale of an A46 built in 1995. The boat had been sailed a great deal - across the Pacific, twice across the Atlantic, and cruised all over the place. She had been well maintained, had recently been painted and the sails were new. Except for some of the older electronics it was not at all apparent that it wasn't a new or nearly new boat. Her last selling price was 20% more than she cost brand new in 1995. Not bad! Okay, so if you had bought T-bills in 1995 instead of a boat you'd have more money now but have you tried to sail a pile of paper?

Can they be singlehanded?

Absolutely. That's the whole idea. These are long distance cruising sailboats and by definition they will often be sailed shorthanded. In many cases that means double handing, which in effect is not much different than single handing because most of the time there is only one person on watch and he/she has to be able to perform most sailing functions alone.

What design characteristics make a boat safe to sail singlehanded?

Visibility. Collision is a major risk. One person on watch needs to be able to easily see all around the boat- especially forward. It is also essential to be able to see well to safely maneuver in crowded harbors, get into docks, etc..

Easy sail handling and reefing. Leading all sail controls to a secure cockpit in the middle of the boat makes all sail handling safe and simple. You do not need to leave the cockpit to tack, gybe or reef. The sides of the cockpit are 10' inboard of the lifelines. It is not possible to fall out of the cockpit.

A protected watch keeping station. Fatigue is the mother of most sailing accidents. Having a watch station where you remain warm, dry and protected can mean the difference between being alert and safe or exhausted and dangerous.

Are there daggerboards or centerboards to aid upwind performance?


If a cat is going to sail upwind really well it needs deeper hydrofoils than the shallow draft fixed fin typical of most cats. The majority of Atlantic Cats have used vertically retracting dagger boards but some A55's were built with “swing up” centerboards. There are pros and cons to each type. The important thing is that there be a well shaped hydrofoil under the boat to allow it to claw to windward.

Why are there fixed fins on the hulls of the Atlantic Cats?

There are many reasons for having a fixed fin on a cruising boat. Here is my thinking:

Because we are designing cruising boats it is essential that they be able to take occasional hard groundings without sustaining major damage. Some of the high performance “cruising cats” promoted today will, upon contact with the bottom, break off their rudders, bend the props into useless shapes and risk large areas of damage to the hull bottoms. In contrast, the Atlantic Cats are designed to survive contact with the bottom with little risk of significant damage.

As one of the few certainties in life, you know that the hull fin being the deepest part will be the “bumper” that will take the vast majority of grounding impact. For that reason we make the fins VERY strong. The base of the fin is a thick single skin epoxy/glass laminate that is sledge hammer proof. The fin side laminate is doubled up as well resulting in an extremely stout structure. The fin is not that long fore and aft but it is plenty long enough for the boat to sit on or in the case of grounding, bounce up and down on for hours.

One of my designs without a fin, a Hammerhead 54 trimaran, went on the reef in the Bahamas two years ago. The surf conditions were quite benign but the tide was falling and they got stuck. Without a fin to support the boat the hull settled onto the coral, bouncing against it on every wave. Within hours two thirds of the main hull bottom had been torn away by the reef. So much of the bottom was missing that the engine fell out! Fortunately, the shallower floats of the tri held the boat up as the main hull was ground away and allowed the boat to be towed off the reef and eventually repaired. If it had been a cat without fins and two torn out bottoms it would still be on the reef as nothing would have been able to tow it off.

Contrast this to an Atlantic 48 Cat that broke it’s mooring in Grenada and fetched up on a reef . Again conditions were moderate but she spent some time there bouncing on the coral. She had only scratches and minor gouges on the fins, without any damage to hull, props or rudders.

Trying to beat some bad weather, Kate and I sailed Javelin into a very dark and unmarked anchorage in Belize. Charts were sketchy, it showed a shoal in the middle of the bay but it was so dark it was hard to judge where that might be. Motoring slowly with a following breeze the bottom rose up so fast we came to a sudden grinding stop before there was a chance to react. All I know about the bottom is that it wasn’t soft! It sounded like small rocks. Hoping we were not stuck I went to full reverse with both engines and after an anxious few seconds was able to back out of the two trenches the fins left in the bottom.

Now what would have happened in a high performance cat with midship props, deep vertically retracting rudders and no fins?

The first area of contact probably would have been the very deep vertically retracting rudders. These are not “kick up” rudders but “break off on impact” rudders. And they would most likely have snapped off on impact.

The next area of contact would probably have been the tips of the folding props, which extend deeper than the hull body. If this happens the props are usually damaged beyond repair.

Next to hit bottom, the hull grounds out for maybe 15’ to 20’ of hull length and a couple feet of width, depending on the firmness of the seabed. In the best conditions only bottom paint is going to be lost. If there is wave action the hull skin can easily be damaged as it just isn’t designed for point loading because that would add way too much extra weight. And an extra 1/100 th of an inch of Kevlar isn’t going to be much of a barrier. If it is a hard edged bottom and there is any swell you are likely to have very major hull damage.

Motoring off with so much hull bottom in contact with the ground and possibly your props compromised because they are bent, whacking the bottom or sucking up rocks is not going to be easy. Yeah, yeah I know… No one should ever go aground. But I'm not afraid to admit that I go aground now and then. It really isn’t very often, but there have been a couple of hard ones. In every case my boat has escaped damage other than scratches. That’s how a cruising cat should be.

Another reason that a fin is worthwhile it the help it provides maneuvering in close quarters. Twin screw cats are typically very maneuverable, except when the props are so far from the rudders that the prop wash cannot be used by the rudder- but that is another topic. Where a cat can be a real handful is in cross winds. With lots of freeboard and little hull in the water they want to blow sideways. The more hull freeboard and cabin and the shallower the hull form the faster they go sideways. I never realized what a difference the fins made until I tried to dock an Atlantic 55 built without fins at the owner’s insistence. “Yikes, what do I do now!” was my basic response to being blown sideways at a much higher than expected rate.

What about rudder protection?

As result of the hull fins all of the Atlantic Cats have well protected rudders. The fin is deeper than the rudder so whatever impacts the rudder might see on grounding are vastly reduced. Also the likelihood of flotsam impacting the rudder with enough force to damage it is diminished. As such, I elected not to use a retracting or kick up rudder in the Atlantic Cat series. Building any retracting rudder in a way that works properly gets expensive, increases the potential for steering failure and requires increased maintenance. If you don’t need it why do it? Instead we build fixed rudders and the construct the blades, rudder stocks and supporting structure very ruggedly. In half a million sailing miles by Atlantic Cats over a 23 year period there have been exactly ZERO structural failures of the rudder. A couple have had gouges or chunks taken out by rocks but never has one failed to do what it was supposed to do.

Can the boat be beached?

Yes. Of course most cruisers try to avoid any sort of grounding because it wears the precious antifouling paint off the bottom of the boat. But on occasion it is very handy to be able to put the boat on a protected beach near the top of the tide in order to do minor bottom maintenance. A prop can be changed, a bit of antifouling paint touched up or other chores which would normally require a haulout.

Can an Atlantic Cat sink?

No. All the Atlantic Cats are inherently buoyant and cannot sink. There are, however differences between them in the amount of positive buoyancy. The foam cored boats will typically float higher if flooded than the older wood/epoxy designs.

Can an Atlantic Cat capsize?

Yes. Any catamaran can be capsized. There are two causes for capsize; the first is wind induced capsize, the second is wave capsize. My book, “The Cruising Multihull” goes into this subject in considerable detail. The short answer is that wind capsize is almost always due to “operator error” and is most easily avoided. Wave capsize due to horrible conditions is something that the operator can do less to avoid, but there are techniques that can be used to help keep the boat upright.

Have any Atlantic Cats capsized?

As of September 2010 two Atlantic Cats have capsized. An Atlantic 42 overturned on Lake Michigan, an event that was solely wind induced. There were no injuries, the boat was recovered with minimal damage and is sailing today. This capsize was very easily avoided if the captain had been paying attention to the boat rather than his computer hard drive!

In July of 2010, an Atlantic 57 overturned in the western Pacific. It was also a wind induced event, and the crew was unharmed. There is extensive information about this event at Anna Capsize.

Should a liferaft be carried?

This is a decision that every sailor needs to make based on their expected destinations, the type and size of boat, the experience of the crew, the time of year and conditions expected.

Historically speaking, abandoning an unsinkable vessel to a liferaft has often diminished the chances of the crew surviving. A flooded or capsized multihull can (but not always) offer a much better survival platform than a small inflatable raft. However, some multihull designs may not float high enough if flooded to offer enough protection to the crew. There is a saying that the only time you want to get into a raft is when you are climbing UP into it.

Do you carry a liferaft?

On my last two cruising boats (one trimaran, one catamaran) I have not carried a raft because in my judgment these boats, even if capsized or flooded, would offer better protection than a raft.

What about fire?

Not many yachts have had to be evacuated at sea due to fire, although it could happen. If this were to happen on my own cat I think I would still prefer to get into the 11' inflatable dinghy with an outboard motor than a raft.

Is there enough ventilation?

One of the key requirements for cruising in warm places is having excellent ventilation. As a breed the Atlantic cats have superior ventilation. There are opening deck hatches about every 8 feet throughout the accommodation plan. There are also opening ports in the hull sides and more importantly opening ports that are positioned in places sheltered from spray so that they can be left open under way.

However the main contributor to great ventilation is the forward facing door from the pilot house into the cockpit. As I sit here now typing the full tradewind breeze keeps me cool inside the pilothouse as it flows through the open doorway. We have hatches and an aft facing door in the pilothouse too- like most other cats- but these are just too small to combat the heat generated within the large pilothouse.

Coming aboard late in the afternoon after the boat has been closed up for hours it is impressively hot inside, maybe 120 degrees F. Open the forward door and all the hatches and in minutes the heat is gone replaced by a lovely breeze.

Some of the production designs such as Catana, have eliminated almost all of the deck hatches. I have no idea how they can ventilate the boat well enough to stay comfortable but recently I was anchored next to one and the gen-set ran constantly so my best guess is they rely on air conditioning instead of ventilation.

Can I have the 'galley up' arrangement?

This question comes up often. In the smaller Atlantic Cats moving the galley into the pilothouse would use up so much of the available space that there would be room for little else. In contrast the galley in the hull is superb, even in the Atlantic 42. There is lots of storage space, tons of counter space, plenty of room for refrigeration, microwave and the elbows of more than one cook.

The primary objection most people have to locating the galley in the hull is that they would feel cut off from conversation in the pilothouse and confined in a tight space. The Atlantic Cats combat this feeling with an extra wide access to the galley that allows communication between people in the pilothouse and galley.

After seeing how well the galley works in real life, most Atlantic Cat owners agree whole heartedly that it is in the right place and would not wish to move it.

The benefits to the existing galley plan are: 1) larger, more functional galley area; 2) easier and safer cooking in rough weather because there are more places for the cook to brace against- freeing both hands.; 3) keeps the galley mess out of the dining and lounging area; 4) Less disturbance to the watch when cooking at night.

Can I use a carbon mast?

Yes. The first A46 launched in 1986 had a wood/carbon composite wing mast so we have a long history with it. More recently, all of the new A57's have had carbon masts. There are some advantages, mostly in weight saving, and you pay a substantial premium for that. Typically a carbon mast costs two to three times what an alumium mast costs. The weight savings - actual, not advertised - is typically a couple of hundred pounds. Some owners find this attractive, others do not. Theoretically a carbon mast should last longer as carbon fiber is very good in fatigue resistance. There are some potential electrolytic corrosion issues with carbon but it holds paint better than aluminum so it should look good for a long time too.

Why don't you use a wing mast?

Some of the early Atlantic cats had wing masts, as did my trimaran Juniper. I know these rigs fairly well and have built several wing masts myself.

On balance, for a cruising cats like these, I see little to be gained for the additional expense and significant additional complication of a rotating wing mast. It is difficult to find a spar builder who can do a good job building a wing mast, and when you do the cost is often quite high. The weight is also greater than a non-rotating mast. Then you run into problems mounting nav lights, instruments, radar and other things on a mast that turns 50 degrees side to side. In addition halyard leads become more complex and prone to chafe. If someone is dead set on it, a wingmast can be designed for many of the Atlantic Cats, but in general I think there are better alternatives.

Can I use synthetic standing rigging?

In recent years there have been many interesting super strong fibers brought to market. Some of these fibers can be made into standing rigging. Kevlar, Spectra, PBO and carbon fibers are now all used in various forms for stays and shrouds. There is no doubt that substantial weight can be saved over SS wire so the top racing boats use synthetic rigging exclusively. But the question remains, is this stuff suitable for cruising boats?

At more than 5 times the cost of wire, certainly the cost is high, but in relation to the weight saved it is not too bad. Where I start to have reservations is when reading the fine print from the makers of synthetic shrouds. Cautions abound. Don't let the sunlight get to the fiber! Don't allow the protective sheathing to be broken by batten chafe! Replace all rigging in 3 years! And in the case of PBO, don't EVER let it get wet! Get wet? On a boat surrounded by ocean and it can't get wet? Whether the rigging providers are playing CYA or being realistic is a difficult question to answer. What I do know is this:

Every fiber has it's own characteristics of stretch, fatigue life, creep, UV and chemical resistance.

Looking at the total picture I have yet to see products that can be put up and ignored for 5 and 10 years the way we are able to do with type 316 SS wire. However, there is a new carbon rigging product that might come close. Recent testing results on rigging that had completed a round the world race showed little or no degradation of strength. That is very significant and worth closer investigation. Eventually SS wire will be replaced with something lighter and hopefully equally or more durable. I just don't think we are there yet.

Why don't you build hulls out of wood?

Wood/epoxy is an excellent boat building material if handled properly. Many of the first Atlantic cats were built of wood/epoxy and these boats have held up well over the years. But as the demand for Atlantic cats has grown, it made sense to use moulds where possible to eliminate the need to build and fair the same hull over and over again. There is no faster way to construct a lightweight and strong hull than out of a female mould. It translates into cost savings for the boat owner as well a better resale value.

Why don't you build hulls out of carbon fiber?

Carbon fiber, like all materials, has unique properties. In yacht construction we are often trying to obtain structural stiffness at low weight. Carbon fiber is excellent for this and we use lots of it in certain places. However, the flip side to low stretch and stiffness under load is often some “brittleness” on impact. Carbon laminates can be quite thin and still be strong enough for sailing loads but not strong enough for localized impact loads. And a hull is the most likely part of the boat to see impacts. The other issue is hull noise. Carbon laminates resonate more strongly than glass fiber when thumped by waves or banging hardware. That translates into much greater noise levels below deck which are at best distracting and at worst terrifying. Maybe this reason sounds silly to the racing sailor, but in my opinion the attainable speed of a performance cruising cat is limited more by crew comfort than anything else.

Can I get an Atlantic Cat in aluminum?

Metal has it's advantages and I have looked at this in detail. The major drawback to aluminum use in a cat is weight. Metal, anyway you slice it, adds considerable additional weight compared to epoxy composite. The typical 3mm aluminum hull plating with frames and stringers at the required intervals weighs about 50% more per unit area than foam/glass/epoxy. THEN if you want a true equivalent you need to insulate the aluminum hull and deck for thermal and sound and then cover the insulation for looks which adds another big chunk of weight. If it is to be painted outside aluminum normally requires lots of fairing putty- still more weight. At the end of it all you have a boat that sinks unless you add special provisions- even more weight.

Can I get one in steel?

No. Steel is far too heavy for a performance catamaran.

Why don't you carry the anchor under the net like the charter cats?

Good question. At first glance this seems like a reasonable idea; the anchor is located off the bows and all components are stowed neatly in one place.

But on closer inspection I have several problems with this arrangement.

The anchor rode is attached to the boat near the mid point fore and aft. Any boat is very unstable at anchor with the rode cleated in this position, yawing violently from side to side. So it requires using a bridle every time you anchor. That in itself is a nuisance because an A-cat will ride happily to a single anchor rode most of the time so making up a bridle and taking it off is additional hassle that is not needed.

When you need a bridle it is typically because it is quite windy and what you'd like to be able to do also is put out more scope. The way most “underwing anchor” cats are rigged in order to increase the scope you first have to pull in a bunch of scope to first disconnect the bridle. In an area with poor holding shortening scope is the last thing you want to be doing when the wind pipes up.

Yet another important issue is what happens when you put out two anchors. When hanging on two anchors for any length of time, invariably the two rodes twist around each other. Before making any adjustments or retrieving either anchor the twists must first be unwrapped. The easy and safe way to do this is, while standing on deck, taking the bitter end of one rode off, coiling it up and unwrapping it around the other rode. If you must get under the boat in the dinghy to do this you will be limited to near calm conditions and that could cause a big problem. Not long ago I watched a neighboring boat hoisting their anchor. Along with it came a 10' long chunk of tree that the anchor chain had wrapped itself around. By pulling the chain up close to the wrap the crew was able to reach down and undo the mess. It would not have been possible had it all been inaccessible under the bow net.

Why don't you offer electric drives?

As of May 2009, I have yet to see an electric drive system that offers any net improvements or advantages over a conventional diesel engine coupled to a propeller. Yes, I have heard the hype and claims, I have just not seen examples demonstrating the performance promised. In fact the examples have been SO FAR AWAY from the promised performance that I have little expectation that anyone will deliver the goods soon.

The subject can get complex as there are several ways you can go about using electric propulsion. But the long and short of it is that for use in a long distance cruising boat you need several things from the auxiliary engine;

Performance. It is a great thing to be able to motor at reasonable speed. And it is essential that you have enough power to be able to motor against strong winds in a harbor or other confined area.

Range. Yeah, you can sit and wait for the wind (been there done that, I have cruised two engineless boats over 10,000 miles) or you can keep moving. People sometimes go overboard on their requirement for range so I hesitate to say what is right or enough range under power. And that will of course vary depending on the region and time of year you are sailing. From my experience I would say being able to motor a couple hundred miles is extremely handy. If you are going to carry an engine in the boat at all it makes sense to be able to motor at least that far. Many cruisers would triple that number or more as their baseline requirement.

Reasonable weight. We are talking multihulls here and weight control is important if you are going to realize the benefits of sailing a catamaran. The reason the world runs on diesel engines is that diesel fuel has such incredible energy density. As a consequence diesel is available all over and is still very cheap compared to the alternatives.

Reliability. Bleeding edge equipment has little application to cruising boats that frequent remote places. The basic diesel engine and drive system that most people use can be serviced in most parts of the world.

Cost. This is always important regardless of what an enthusiastic supporter of alternative propulsion might say.

What is the current state of electric propulsion?

I am no expert, I just repeat what I have been told by various owners and boat builders who have used or installed some of these systems.

The bottom line is that I have yet to hear a single complimentary review of the whole system. They have been expensive, heavy, prone to problems, difficult to install and worst of all the performance has been way below expectations.

Performance: Javelin, my conventional diesel powered Atlantic 55 can power along for hours at 10 knots at full throttle. I have not heard of any electric drive examples that do much better than 7 knots and most are way below that.

Range: A pure electric drive system in a catamaran run off a one ton battery bank will typically provide a range of less than 10 miles! Okay add two more tons of batteries and you might have 30 mile range. But what did you just do to the sailing ability of the boat by adding all that extra weight? Answer; ruin it.

Weight: Currently, there is no way to store enough electrical power to propel a boat any distance at anything close to an acceptable weight. This is going to be the primary limitation until there are huge advances in battery technology (which may come, but who knows when).

Cost: Last week I was meeting with a boatbuider who had recently completed a 55' catamaran with electric drives. We spoke in detail about the installation problems and costs. He was still assembling the post construction cost numbers but was certain the drive system cost in excess of $100,000. This boat could run less than one hour from it's battery bank. For cost comparison: in the Atlantic 57 we use 55 hp diesel saildrives. The engines and saildrives cost about $12,000 each (wholesale). The props, exhaust system, throttle and shift controls add roughly another $10,000 in parts. Add labor and you are still less than half the cost of the electric drive system.