Episode Details

A catamaran is simply two parallel hulls of equal size, and that wide stance gives it form stability without the heavy lead keel a monohull needs, so it sits light and shallow in the water. The design was pioneered by Austronesian peoples, and it carried them across the Pacific and Indian Oceans as far as Madagascar. Anthropologists of the 1930s and 1940s assumed catamarans evolved from outrigger canoes, but later researchers showed the reverse: two logs lashed into a raft became twin carved hulls, then asymmetric double canoes, then the single outrigger, then the double outrigger or trimaran. Far Pacific sailors kept catamarans and single outriggers and learned to shunt, moving the sail to the other end so the outrigger always faced the wind. The name itself is a mix up, from the Tamil kattumaram, logs bound together, a single hulled raft of three to seven trunks.

In Europe, William Petty's twin hulled merchant boat of 1662 was mocked and failed. Then in 1876 Nathaniel Herreshoff's Amaryllis flew past the deep keeled yachts at the New York Yacht Club's centennial regatta, and the club banned catamarans from regular classes, a ban that held back Western development into the 1970s. Outsiders kept experimenting until Hobie Alter's beach cats, with over 100,000 Hobie 16s built, brought them to the public. The episode explains why narrow hulls dodge the bow wave speed limit and generate apparent wind for rigid wing sails, why catamarans resist capsizing up to seven times better than monohulls of the same width, and why they lose badly to monohulls at hauling bulk cargo.

• Leonardo Torres Quevedo patented a flexible twin hulled steel vessel in 1916 to absorb wave torque.
• Eric de Bisschop sailed a Polynesian style double canoe from Hawaii to France in the 1930s.
• The Prout brothers used a mast aft rig so the jib lifted the bows and prevented pitchpoling.
• Frederick G. Creed patented the SWATH design, with submerged torpedo hulls on thin struts, in 1938.
• Steve Fossett's 125 foot PlayStation hit 50 knots, and the solar powered Tûranor PlanetSolar circled the globe.