Catamarans, often called 'cats' in boating circles, are twin-hulled watercraft noted for their speed and stability in open water. Many long-distance sailing races are won by these boats, although traditional boat designers haven't always embraced their unorthodox features. This type of boat can be powered by sails placed forward or by engines mounted in the central rear.
The first catamarans were designed and sailed by affluent fishing tribes working in the Indonesian area of the Indian ocean. The name is an anglicized pronunciation of the Tamil word kattumaram, literally translated as logs tied together. Instead of using the traditional single-hulled design of a canoe, the first versions of this boat used two separate pontoons held apart by a single deck and diagonal strapping, with a sail mounted on the forward section of the deck. Eventually, their speed and maneuverability proved useful in the defense of Indonesian trade routes.
These boats are still considered to be among the fastest sailing boats available. Typically, catamarans use deep V-shaped hulls to cut through the water, creating a phenomenon known as planing. When running at full speed, boats of this design may only have a few inches of the hulls remaining in the water. Because their hulls are generally thinner than those of monohull boats, they're are also noticeably lighter. The stability of two hulls and a central deck eliminates the need for additional ballast.
This is not to say that catamarans are easier to sail than other sailboat designs. Pilots often have to lean out of the opposite hull in order to counterbalance the boat during a turn. They have a tendency to capsize if the sails are not reversed in time. Pilots cannot always follow a straight course while steering them — a series of zig-zags may be required.
Powered catamarans can be very large indeed, with some top-end models rivaling yachts and small cruise ships. Military ship designers are also creating fortified versions for use as swift-moving transporters. Small sail-powered types can be purchased for a few thousand US dollars, while luxury models may run into the hundreds of thousands of dollars. Special trailers may be required to transport catamarans over standard roadways, since the boat must be tilted to meet load width regulations. Storage slips on the water may also be difficult to obtain because of the boat's wider dimensions.