Whether you enjoy power or sail, the rising popularity of multihulls is hard to dispute.
Catamarans and trimarans have come a long way since the days of beachfront rentals and radical racing, as consumer demand for larger, faster and more stable boats has pushed many buyers in the direction of a multihull.
Performance CruisingA smooth ride on a Telstar 28. Multihulls now dominate charter fleets in the Caribbean and other popular destinations. They pack the largest boat shows, such as Miami's annual event, which drew more than 50 models this year. Indeed, the next America's Cup will be a contest between two massive catamarans.
For those raised on a single hull, the popularity can be vexing. But a look at the advantages native to multi-hull designs can explain a great deal. After all, they are hardly a new idea.
ANCIENT DESIGN
Multihull boats have been around so long that their origin is lost in the mists of prehistory. The widely scattered islands of the Pacific, Indian Ocean and East Africa were settled by people using various configurations of multihulls. By the time the first Europeans sailed into the area, the boat type was well established. Explorers brought back amazing tales of these boats, but European (and later, American) experiments with the boats were few.
The modern multihull that we are familiar with can trace its birth to the period just after World War II. Designer Woody Brown in Hawaii began to develop lightweight catamarans around 1947. The Prout brothers in England began building catamarans in the mid 1950s. The name most associated with early trimaran development was Arthur Piver in the San Francisco Bay area. He wasn't the first at promoting the type, but he was the best.
All of the early builders were using materials like plywood and fiberglass, and applying them to boats inspired by the ancient Polynesian prototypes. Most of these early developers were working outside mainstream yacht design, so there was a certain degree of trial and error. Because of the speed of the light, narrow hulls, they were quickly adopted by racers. This led to some spectacular – and well reported – breakups until designers better understood the high degree of stress placed on the boats.
LONG, NARROW AND LIGHT
Multihulls are based on two concepts. The first is that long, narrow hulls move more easily through the water. The second is that stability can be achieved through buoyancy rather than ballast.
Catman CatsMare Bello, a serious power catamaran.
A long, narrow hull encounters less resistance going through the water. Think of a racing shell compared to a common rowboat. The result is that it takes less power to move such a boat, or that the boat will move faster with the same amount of power. With the exception of catboats, the average monohull today has a length-to-beam ratio (what multihullers call a "fineness ratio") of about 3-to-1. A fineness ratio of 7-to-1 is common in multihulls, and many – especially the speed machines – go as high as 16-to-1.
How fast can a sailing multihull go? Last summer the 105-foot trimaran Groupama III sailed across the Atlantic, a distance of 2,925 miles, in less than 100 hours. It also set a record for a single day's run of 794 miles. The average multihull you see on the waters today will be more conservative than the racing machines. But it is certainly no slug.
Of course, a narrow beam means less room for accommodations below deck, so cruising multihulls expand the hull above the waterline. This shows up as wings on a trimaran; on a catamaran, much of the accommodation is on the bridge deck.
