What Is a Catamaran?

A catamaran (/ktmrn/) (informally, a “cat”) is a multi-hulled watercraft featuring two parallel hulls of equal size. It is a geometry-stabilized craft, deriving its stability from its wide beam, rather than from a ballasted keel as with a monohull boat. Catamarans typically have less hull volume, smaller displacement, and shallower draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic resistance than comparable monohulls, requiring less propulsive power from either sails or motors. The catamaran‘s wider stance on the water can reduce both heeling and wave-induced motion, as compared with a monohull, and can give reduced wakes.

Catamarans range in size from small sailing or rowing vessels to large naval ships and roll-on/roll-off car ferries. The structure connecting a catamaran‘s two hulls ranges from a simple frame strung with webbing to support the crew to a bridging superstructure incorporating extensive cabin and/or cargo space.

However, the original kattumaram did not refer to double-hulled boats at all, but to a type of single-hulled raft made of three to seven tree trunks lashed together. Two canoes bound together developed directly from minimal raft technologies of two logs tied together. This would also explain why older Austronesian populations in Island Southeast Asia tend to favor double outrigger canoes, as it keeps the boats stable when tacking .

Crisp described it as “a fast sailing fine sea boat; she traded during the monsoon between Rangoon and the Tenasserim Provinces for several years”. Later that century, the American Nathanael Herreshoff constructed a double-hulled sailing boat of his own design (US Pat. Her debut demonstrated the distinct performance advantages afforded to catamarans over the standard monohulls.

It was as a result of this event, the Centennial Regatta of the New York Yacht Club, that catamarans were barred from regular sailing classes, and this remained the case until the 1970s. [23] The claimed advantage of this sail plan was to diminish any tendency for the bows of the vessel to dig in. Hobie 16 beachable catamaranIn the mid-twentieth century, beachcats became a widespread category of sailing catamarans, owing to their ease of launching and mass production.

[[HSC Francisco ]]; the world’s fastest passenger ship Catamarans have two distinct primary performance characteristics that distinguish them from displacement monohull vessels: lower resistance to passage through the water and greater stability (initial resistance to capsize). Choosing between a monohull and catamaran configuration includes considerations of carrying capacity, speed, and efficiency. Vangohh Seafarer , a catamaran motor yacht berthed at Straits Quay, Georgetown, Pulau Pinang, MalaysiaOne measure of the trade-off between speed and carrying capacity is the displacement Froude number (Fn V ) , [40] compared with calm water transportation efficiency .

[42] It uses a reference length, the cubic root of the volumetric displacement of the hull, V , where u is the relative flow velocity between the sea and ship, and g is acceleration due to gravity : FnV=ugV1/3{\displaystyle \mathrm {Fn_{V}} ={\frac {u}{\sqrt {gV^{1/3}}}}} Calm water transportation efficiency of a vessel is proportional to the full-load displacement and the maximum calm-water speed, divided by the corresponding power required. It was first used in the 1960s and 1970s as an evolution of catamaran design for use as oceanographic research vessels or submarine rescue ships.

Larger wetted surface, which causes higher skin friction drag Significant reduction in wave-induced drag, with the configuration of struts and submerged hull structures Lower water plane area significantly reduces pitching and heaving in a seaway No possibility of planing Higher sensitivity to loading, which may bring the bridge structure closer to the water The spanning bridge deck may be configured with some of the characteristics of a normal V-hull, which allows it to penetrate the crests of waves. Emirates Team New Zealand’s AC72 Aotearoa on foils in San Francisco BayTechnological advances catamerans have over traditional monohull craft include foils that lift racing catamarans out of the water, capacious and stable cruising vessels, and racers that have achieved average speeds on the open ocean, comparable to much larger vessels.

Recreational and sport catamarans typically are designed to have a crew of two and be launched and landed from a beach. Performance versions often have trapezes to allow the crew to hike out and counterbalance capsize forces during strong winds on certain points of sail. This represented a break from the traditional monohulls that had always been sailed in previous America’s Cup series.

The Race ” helped precipitate this trend; it was a circumnavigation challenge which departed from Barcelona, Spain, on New Year’s Eve, 2000. Because of the prize money and prestige associated with this event, four new catamarans (and two highly modified ones) over 100 feet (30 m) in length were built to compete. The frame of the tourist catamaran can be made of both aluminum (duralumin) pipes and from felled tree trunks.

[57] A cata-raft design has been used on the Colorado River to handle heavy whitewater, yet maintain a good speed through the water. Cruising sailors must make trade-offs among volume, useful load, speed, and cost in choosing a boat. Choosing a catamaran offers increased speed at the expense of reduced load per unit of cost.

In addition to greater speed, catamarans draw less water than do monohullslittle as 3 feet (0.91 m)and are easier to beach. Tarjan adds that cruising catamarans boats can maintain a comfortable 300 nautical miles (350 mi; 560 km) per day passage, with the racing versions recording well over 400 nautical miles (460 mi; 740 km) per day. ^ The Origins and Ethnological Significance
Of Indian Boat Designs JAMES HORNELL
Director of Fisheries, Madras Government
The Origins and Ethnological Significance
Of Indian Boat Designs
Memoirs of the Asiatic Society of Bengal
Calcutta 1920 ^ a b c Mahdi, Waruno (1999).

A treatise on marine architecture, elucidating the theory of the resistance of water : illustrating the form, or model best calculated to unite velocity, buoyancy, stability, strength, etc., in the same vessel : and finally, adducing the theory of the art of shipbuilding . ^ Sampsell, Lorillard D. (March 1898), “The Southern Yacht Club of New Orleans” , Outing: Sport, Adventure, Travel Fiction, Volume 31 ^ Counce, Oliver J. (2000), “The sesquicentennial of the Southern Yacht Club of New Orleans, 1849-1999 : 150 years of yachting in the Gulf South”, Metairie Franklin Southland Printing , OCLC 46836336 ^ The Voyage of the Kaimiloa , London, 1940 (translated from French: Kaimiloa : D’Honolulu Cannes par l’Australie et Le Cap, bord d’une double pirogue polynsienne ), Editions Plon, Paris, 1939 ( Au del des horizons lointains 1 ).

CS1 maint: numeric names: authors list ( link ) ^ “Hobie 16 2012 Class Report 2012” (PDF) . ^ “Oracle Team USA completes greatest comeback in America’s Cup history, defeating Emirates New Zealand” .

What is the difference between a boat and a catamaran?

The main difference is the shape of the boat : a yacht or traditional sailing boat has one hull (the bottom of the boat) which sits in the water, but a catamaran is a ‘multi-hull’ so has two hulls or points of contact with the sea, with a platform across the top which joins the two hulls together into one boat shape.

What is the purpose of a catamaran?

Sailing catamarans are used for recreational purposes by people who want to experience the life of a sailor. Catamaran sailing does not involve any place for residing in the boat. In other words, catamaran sailing can also be referred to as catamarans that are used as yachts.

What classifies as a catamaran?

In simplest terms, a catamaran is defined as a boat with two hulls. The term is derived from the Tamil word, kattumaram, which means logs bound together and the first of these designs were used for fishing.

What is special about a catamaran?

Catamarans typically have less hull volume, smaller displacement, and shallower draft (draught) than monohulls of comparable length. The two hulls combined also often have a smaller hydrodynamic resistance than comparable monohulls, requiring less propulsive power from either sails or motors.

When it comes to sailing, possessing unrestricted access to the top-notch and the most innovative yachts do make a difference. This is exactly the type of thing that can make your vacation go from ordinary to extraordinary. The Moorings catamarans are developed explicitly by famous boat builders Robertson & Caine, a South African company popular for their Leopard brand of ownership yachts.

Electric davits make lifting the dinghy comfortable, and the luxurious fly bridges provide extra spaces for entertaining and lounging. Navigation A crucial aspect of a charter yacht is safety, which contains seamless and unrestricted access to the control panel and the ability to communicate smoothly with the crew in the saloon, deckhouse, and on deck.

Spotting a catamaran is easy. Simply look at the hulls and count them. Catamarans have two hulls side by side and a relatively large gap between them where you can see light on the other end. Catamarans are distinct from trimarans, which have an additional hull between the two outer hulls.

Additionally, the large section of deck between the hulls of a catamaran is prone to pounding in rough seas, which is loud and uncomfortable. Catamarans can sometimes be twice the width of an equivalent monohull sailboat, which can increase mooring fees and limit docking options.

Traditional full-keel monohull sailboats have a very low center of gravity, which makes them roll in heavy seas but ensures a recovery. As the bow and stern wave of a monohull intersect, they cause drag which limits the top speed of the boat. Catamarans are also more stable than monohulls, as their wide stance and shallow draft reduce the effect of rough water.

Power catamarans are a recent development, as engineers and marine architects now realize they have numerous hydrodynamic advantages over other hull types. The Spearhead class EPF is an expeditionary fast transport vessel designed for carrying capacity and speed. Power catamarans are also used as patrol and utility boats on a much smaller scale, with either outboard or inboard motors.

Houseboats dont always use the catamaran hull type, but its common enough that most major manufacturers offer it as an option. Monohulls have lots of storage space in their hulls and can carry thousands of tons of cargo safely in all weather conditions. Catamarans lack this space and low center of gravity, so theyre not ideal for transporting cargo past a certain point.

A large monohull sailboat can be constructed at low cost from stock plans and reliably sail almost anywhere.

Over the last 20 years, catamarans have seen a massive rise in popularity among charterers, cruisers, and even the casual daysailor. Curious about catamaran sailing? Heres some basic information you need to know:

Catamaran

ACatamarans were invented by the Austronesian peoples which enabled their expansion to the islands of the Indian and Pacific Oceans.Catamarans range in size from small sailing or rowing vessels to large naval ships and roll-on/roll-off car ferries. The structure connecting a catamaran‘s two hulls ranges from a simple frame strung with webbing to support the crew to a bridging superstructure incorporating extensive cabin and/or cargo space.

History[edit]

Catamarans from Oceania and Maritime Southeast Asia became the inspiration for modern catamarans. Until the 20th century catamaran development focused primarily on sail-driven concepts.

Etymology[edit]

The word “catamaranis derived from the Tamil word,

Development in Oceania and Asia[edit]

Catamaran-type vessels were an early technology of the Austronesian peoples. Early researchers like Heine-Geldern (1932) and Hornell (1943) once believed that catamarans evolved from outrigger canoes, but modern authors specializing in Austronesian cultures like Doran (1981) and Mahdi (1988) now believe it to be the opposite.Two canoes bound together developed directly from minimal raft technologies of two logs tied together. Over time, the double-hulled canoe form developed into the asymmetric double canoe, where one hull is smaller than the other. Eventually the smaller hull became the prototype outrigger, giving way to the single outrigger canoe, then to the reversible single outrigger canoe. Finally, the single outrigger types developed into the double outrigger canoe (or trimarans).This would also explain why older Austronesian populations in Island Southeast Asia tend to favor double outrigger canoes, as it keeps the boats stable when tacking. But they still have small regions where catamarans and single-outrigger canoes are still used. In contrast, more distant outlying descendant populations in Oceania, Madagascar, and the Comoros, retained the double-hull and the single outrigger canoe types, but the technology for double outriggers never reached them (although it exists in western Melanesia). To deal with the problem of the instability of the boat when the outrigger faces leeward when tacking, they instead developed the shunting technique in sailing, in conjunction with reversible single-outriggers.Despite their being the more “primitive form” of outrigger canoes, they were nonetheless effective, allowing seafaring Polynesians to voyage to distant Pacific islands.

Traditional catamarans[edit]

The following is a list of traditional Austronesian catamarans:

Western development[edit]

The first documented example of double-hulled sailing craft in Europe was designed by William Petty in 1662 to sail faster, in shallower waters, in lighter wind, and with fewer crew than other vessels of the time. However, the unusual design met with skepticism and was not a commercial success.The design remained relatively unused in the West for almost 160 years until the early 19th-century, when the Englishman Mayflower F. Crisp built a two-hulled merchant ship in Rangoon, Burma. The ship was christenedLater that century, the American Nathanael Herreshoff constructed a double-hulled sailing boat of his own design (US Pat. No. 189,459).In 1936, Eric de Bisschop built a Polynesian “double canoe” in Hawaii and sailed it home to a hero’s welcome in France. In 1939, he published his experiences in a book,Roland and Francis Prout experimented with catamarans in 1949 and converted their 1935 boat factory in Canvey Island, Essex (England), to catamaran production in 1954. TheirIn the mid-twentieth century, beachcats became a widespread category of sailing catamarans, owing to their ease of launching and mass production. In California, a maker of surfboards, Hobie Alter, produced the 250-pound (110 kg) Hobie 14 in 1967, and two years later the larger and even more successful Hobie 16. As of 2016, the Hobie 16 was still being produced with more than 100,000 having been manufactured.Catamarans were introduced to Olympic sailing in 1976. The two-handed Tornado catamaran was selected for the multihull discipline in the Olympic Games from 1976 through 2008. It was redesigned in 2000.The Australian island Tasmania became the site of builders of large transport catamarans—Incat in 1977

Performance[edit]

Catamarans have two distinct primary performance characteristics that distinguish them from displacement monohull vessels: lower resistance to passage through the water and greater stability (initial resistance to capsize). Choosing between a monohull and catamaran configuration includes considerations of carrying capacity, speed, and efficiency.

Resistance[edit]

At low to moderate speeds, a lightweight catamaran hull experiences resistance to passage through water that is approximately proportional to the square of its speed. A displacement monohull, by comparison, experiences resistance that is at least the cube of its speed. This means that a catamaran would require four times the power in order to double its speed, whereas a monohull would require eight times the power to double its speed, starting at a slow speed.

Stability[edit]

Catamarans rely primarily on form stability to resist heeling and capsize.

Tradeoffs[edit]

One measure of the trade-off between speed and carrying capacity is the displacement Froude number (FnLarge merchant vessels have a Fn

Applications[edit]

Two advances over the traditional catamaran are theSWATH reduces wave-generating resistance by moving displacement volume below the waterline, using a pair of tubular, submarine-like hulls, connected by pylons to the bridge deck with a narrow waterline cross-section. The submerged hulls are minimally affected by waves.SWATH vessels compare with conventional powered catamarans of equivalent size, as follows:Wave-piercing catamarans employ a low-buoyancy bow on each hull that is pointed at the water line and rises aft, up to a level, to allow each hull to pierce waves, rather than ride over them. This allows higher speeds through waves than for a conventional catamaran. They are distinguished from SWATH catamarans, in that the buoyant part of the hull is not tubular. The spanning bridge deck may be configured with some of the characteristics of a normal V-hull, which allows it to penetrate the crests of waves.Wave-piercing catamaran designs have been employed for yachts,

Sport[edit]

Recreational and sport catamarans typically are designed to have a crew of two and be launched and landed from a beach. Most have a trampoline on the bridging structure, a rotating mast and full-length battens on the mainsail. Performance versions often have trapezes to allow the crew to hike out and counterbalance capsize forces during strong winds on certain points of sail.For the 33rd America’s Cup, both the defender and the challenger built 90-foot (27 m) long multihulls. Société Nautique de Genève, defending with team Alinghi, sailed a catamaran. The challenger, BMW Oracle Racing, used a trimaran, replacing its soft sail rig with a towering wing sail—the largest sailing wing ever built. In the waters off Valencia, Spain in February 2010, the BMW Oracle Racing trimaran with its powerful wing sail proved to be superior. This represented a break from the traditional monohulls that had always been sailed in previous America’s Cup series.On San Francisco Bay, the 2013 America’s Cup was sailed in 72-foot (22 m) long AC72 catamarans (craft set by the rules for the 2013 America’s Cup). Each yacht employed hydrofoils and a wing sail. The regatta was won 9-8 by Oracle Team USA against the challenger, Emirates Team New Zealand, in fifteen matches because Oracle Team USA had started the regatta with a two-point penalty.Yachting has seen the development of multihulls over 100 feet (30 m) in length. “The Race” helped precipitate this trend; it was a circumnavigation challenge which departed from Barcelona, Spain, on New Year’s Eve, 2000. Because of the prize money and prestige associated with this event, four new catamarans (and two highly modified ones) over 100 feet (30 m) in length were built to compete. The largest,Whitewater catamaran—sometimes called “cata-rafts”—for whitewater sports are widely spread in post-Soviet countries. They consists of two inflatable hulls connected with a lattice scaffold. The frame of the tourist catamaran can be made of both aluminum (duralumin) pipes and from felled tree trunks. The inflatable part has two layers—an airtight balloon with inflation holes and a shell made of dense tissue, protecting the balloon from mechanical damage. Advantages of such catamarans are light weight, compactness and convenience in transportation (the whole product is packed in one pack-backpack, suitable for air traffic standards) and the speed of assembly (10–15 minutes for the inflation).

Cruising[edit]

Cruising sailors must make trade-offs among volume, useful load, speed, and cost in choosing a boat. Choosing a catamaran offers increased speed at the expense of reduced load per unit of cost. Howard and Doane describe the following tradeoffs between cruising monohulls and catamarans:Powered cruising catamarans share many of the amenities found in a sail cruising catamaran. The saloon typically spans two hulls wherein are found the staterooms and engine compartments. As with sailing catamarans, this configuration minimizes boat motion in a seaway.The Swiss-registered wave-piercing catamaran,

Passenger transport[edit]

The 1970s saw the introduction of catamarans as high-speed ferries, as pioneered by Westermoen Hydrofoil in Mandal, Norway, which launched the Westamaran design in 1973.

Military[edit]

The first warship to be propelled by a steam engine, namedIn the early 20th Century several catamarans were built as submarine salvage ships: SMSThe use of catamarans as high-speed naval transport was pioneered by HMASTheFirst launched in 2004 at Shanghai, the Houbei class missile boat of the People’s Liberation Army Navy (PLAN) has a catamaran design to accommodate the vessel’s stealth features.

Benefits of a Catamaran

Are you in search of ultimate comfort while sailing and top-tier relaxation when on your chartered sea tour? If that’s you, then a sailing catamaran is all you need. Unlike a monohull, the catamaran possesses 2 hulls that are joined by crossbeams. Situated in the hulls are the staterooms, each with their own private head. The bridge deck and the deckhouse are utilized as the galley and saloon, and for navigating.Few of the catamarans also have one more level called the flybridge. The Moorings Sailing catamarans offer an ideal vacation place for making memories on the water. Furthermore:

How to Spot a Catamaran

Spotting a catamaran is easy. Simply look at the hulls and count them. Catamarans have two hulls side by side and a relatively large gap between them where you can see light on the other end. Catamarans are distinct from trimarans, which have an additional hull between the two outer hulls.

How do Catamarans Work?

The principle behind the catamaran is simple. You can think of catamarans like cars and monohulls like motorcycles. Catamarans distribute their weight between hulls on either side, whereas monohulls utilize only one hull.Evidently, cars are much more difficult to tip over and can hold much more weight. Additionally, cars are wider, as they have much more contact with the road. Catamarans work in a similar way, as they have a wide stance and contact with the surface on both sides.Obviously, that isn’t the most precise comparison. But the basic principle is the same, and catamarans have a few notable benefits over monohulls.

Catamaran Vs Monohull

Catamarans are easy to distinguish from monohulls. A monohull is just a regular old boat with a single hull. The vast majority of boats and ships are monohulls. Catamarans have two hulls, which are usually sleek and narrow.Here are some comparisons of catamarans and monohulls, along with the advantages twin-hull designs have over most single hull types.

Benefits of Catamarans

Catamarans have numerous benefits. The first is speed. Catamarans produce less drag than monohulls and thus can achieve excessive speeds both under sail and power. They don’t need to plane like monohulls to achieve these high speeds, and they use less fuel.Catamarans are also much more stable than monohulls. They have a wide stance and shallow draft, and many waves and swells can travel between the hulls instead of below them. This effectively reduces an entire axis of movement and prevents catamarans from rolling excessively.

Drawbacks of Catamarans

Catamarans aren’t advantageous in every way, or else we wouldn’t bother building monohulls. The disadvantages of catamarans limit their use to niche commercial applications and high-end yachts. But what are the drawbacks of a twin-hull design?Sailing catamarans don’t follow many of the traditional boat handling rules and characteristics that sailors pass down for generations. Some, such as hull speed limitations, are good to do away with—while others, such as responsiveness, are not.Catamarans aren’t as quick to the helm or responsive as monohulls. There are some exceptions to this rule, but for the most part, you’ll get a lot more feedback from a single-hull vessel. Additionally, the large section of deck between the hulls of a catamaran is prone to pounding in rough seas, which is loud and uncomfortable.Catamarans can sometimes be twice the width of an equivalent monohull sailboat, which can increase mooring fees and limit docking options.The final major drawback of catamarans is a consequence of their stability. Traditional full-keel monohull sailboats have a very low center of gravity, which makes them roll in heavy seas but ensures a recovery.Catamarans have a higher center of gravity, and they can’t right themselves after a knockdown. And though catamarans are less likely to roll, a severe list on a multihull is a much more serious concern than on a ballasted monohull.

Catamaran Vs Trimaran

Catamarans and trimarans are often lumped together, but they have very different design and performance specifications. Trimarans have three hulls, whereas catamarans have two.Trimarans look a lot like catamarans from the side, but a quick glance at the bow or stern can set them apart. Trimarans are faster than catamarans, as they distribute their weight across three hulls instead of two. This helps them stay centered and reduces interference from pitching and rolling.Catamarans are fast, but they lose out to trimarans when going head to head. However, catamarans are much less expensive to build and maintain and often have roomier cabins due to their larger hulls.

Types of Catamarans

There are numerous types of catamarans, and their uses vary widely. The catamaran is one of the oldest and most useful hull types, and some variants have been used for thousands of years. Here are the most common kinds of catamaran boats and their uses.

Sailing Catamaran

Sailing catamarans are probably what you think of when you hear the name. Sailing catamarans are sailboats with two identical hulls connected by a center deck. The largest sailing catamarans are spacious and stable vessels that are capable of serious offshore sailing.Sailing catamarans have a number of notable advantages over monohulls. Monohulls, which are traditional sailboats with a single hull, are limited by a simple concept called hull speed. As the bow and stern wave of a monohull intersect, they cause drag which limits the top speed of the boat.Catamarans are not bound by hull speed limitations, as they have two hulls. Catamarans can go twice or even three times as fast as similar monohulls and achieve excellent travel times.Catamarans are also more stable than monohulls, as their wide stance and shallow draft reduce the effect of rough water. They don’t heel, as the force of the wind is counteracted by the double hulls. Additionally, modern sailing catamarans can ‘wave pierce’ by cutting through swells instead of riding over them.Sailing catamarans come in many shapes and sizes. Small sailing catamarans, such as those used in races and regattas, are known for their speed and relative stability compared to light racing monohulls. Sometimes, they feature a smaller second hull for stability—these are called outriggers.Sailing catamarans have spacious interiors thanks to the large cockpit between the hulls. This cockpit usually contains cooking and eating spaces, a place to sit, and a hallway between the hulls. The hulls usually contain living quarters and often mirror each other.

Power Catamarans

Power catamarans have an even greater variety than sailing catamarans. These vessels are used for everything from party platforms to ferries and patrol boats.Power catamarans are a recent development, as engineers and marine architects now realize they have numerous hydrodynamic advantages over other hull types.Catamarans are much more efficient than other hull types, as they have less drag relative to their size. Additionally, you can build a much larger catamaran with less material. This makes them popular for car and rail ferries, as builders can construct a very wide vessel with two small hulls rather than a narrower vessel with a large single hull.

Military and Commercial Catamarans

Even the military has found a use for the catamaran hull shape. The Spearhead class EPF is an expeditionary fast transport vessel designed for carrying capacity and speed. It has two sharp hulls and a huge cargo capacity.The Spearhead class EPF is 337 feet long, which is about the same length as a WW2 escort destroyer. Yet despite having a similar length and displacement, these catamarans can travel more than twice as fast—43 knots, or nearly 50 miles per hour. Their great speed is a direct consequence of their catamaran hull type.Power catamarans are also used as patrol and utility boats on a much smaller scale, with either outboard or inboard motors. The State of Texas uses catamarans to patrol shallow rivers and lakes. Texas Game Wardens utilize state-of-the-art aluminum catamaran patrol boats, which are fast enough to outrun most fishing boats.There’s another form of power catamaran that you may not have considered. Pontoon boats are technically catamarans, and they’re enormously popular on lakes and rivers throughout the country. Pontoon boats aren’t known for speed, but they’re a great platform for a fun and comfortable outing.

Catamaran Houseboats

The final common type of power catamaran is the two-hulled houseboat. Houseboats don’t always use the catamaran hull type, but it’s common enough that most major manufacturers offer it as an option.Catamaran houseboats have a few notable advantages over monohull designs. For one, they’re easier to build—especially when pontoons are chosen. Additionally, they’re better suited for navigating shallow water. These vessels can support more weight across their two hulls, offer increased stability, and they’re also efficient.