Catamarans - Can Different be Useful?
A catamaran ("cat" for short) is a multi-hulled vessel with two parallel hulls of equal size.
Unlike a monohull, with its heavy lead ballasted keel, a catamaran derives its stability from its wide beam, particularly the distance between the two hulls. Without the keel (and its tremendous weight!) of a mono-hull, a catamaran usually has a much shallower draft, sitting on, rather than in, the water. Its two hulls together can have less wetted area than that of the hull of a mono-hull of the same length. The combination of less wetted area and hulls having much narrower length to beam (width) ratios (typically 10 or 12 to 1), means there can be significantly less resistance and drag, which generally results in significantly faster speeds.
Basic Catamaran Shape
A sailing multi-hull also heels less than a mono-hull, so on a windward course, its sails can use the wind more efficiently. Because there is very little heeling (seldom more than 5
to 10 degrees), the ride is generally more comfortable (and safer) for passengers and crew, in good weather or foul.
The two hulls of a cat are held together by a frame, or a more complex structure. Catamarans of 9 meters or more can have accommodation inside the bridge deck. Catamarans may be driven by sail and/or engine(s). Early examples of modern cats were mainly yachts, but recently some ships and ferries use this hull layout to allow increased speed, stability, and comfort at sea.
For Western boat designers, the concept of a catamaran is relatively new, although they have been used since ancient times by the Dravidian people, in South India, and, independently, in Oceania, where Polynesian catamarans and outrigger canoes made it possible for seafaring Polynesians to travel to the most remote Pacific islands. It is said that Hawaii was discovered and populated, originally, this way.
In recreational sailing, catamarans and trimarans initially met with skepticism by Western sailors who were used to traditional mono-hull designs with a ballasted keel.
A Selective History
Bias? What Bias ?!?!
Already in the 19th century a few cats were built, but they were mostly ridiculed. Later, a well-known and respected American navel architect, Nathanael Herreshoff, received the first U.S. patent on catamaran sailboats (the Amaryllis, 1876) and it immediately displayed a overwhelmingly superior performance at her maiden regatta (the Centennial Regatta on June 22, 1876, off the New York Yacht Club's Staten Island station). At this very event, after protest by the losers, catamarans were barred from all the regular classes and they remained barred until the 1970's. This ban relegated the catamaran to being a mere novelty boat design for many years.
FYI: The irony of course is that Herrshoff was and continues to be seen as a God among men when it came to traditional yacht
design, and even HE couldn't change anyone's mind at that time!