Naval Architecture

It’s been a little over 10 years since foils were introduced on large numbers of racing sailboats, both monohulls and multihulls. In the recreational boating sector, these appendages are no less impractical to integrate on a single hull as they are on two or three. In fact, foils come in many shapes and sizes, and can be found on all kinds of multihulls, including powercats and cruisers. This technical revolution is becoming increasingly accessible and is set to change the way we sail.

A Brief History of Foils Around the World

Contrary to popular belief, foils are not a recent invention. However, their adoption on sailboats and multihulls has been (very) gradual and has only recently become popular. The idea of using underwater blades to lift a boat was developed by an Englishman, Thomas W. Moyet, in 1861, then in 1869 by a French mechanical engineer, Emmanuel D. Farcot. The latter filed patents in which he added lateral load-bearing planes to a boat, whose inclination could be adjusted according to speed. The effect was to lift the boat slightly off the water, thus validating the hydrofoiling principle. The principle was improved in 1878 by London-based John Stanfield and Josiah Clark, while in 1881 Horatio F. Phillips, another Englishman, but an aviation pioneer, created the transverse foiling system for fast ships.
A prototype foiler was built in 1985 by Count Charles de Lambert, a French adventurer and aircraft pilot. This was a catamaran whose two floats were joined by plates underneath. Towed by a horse on the bank, the multihull quickly rose above the water, validating the foiling principle. The inventor continued to improve his invention, going so far as to design a catamaran with five lateral foils and a motor to reach speeds of 40 km/h (25 mph) while skimming the surface of the water. In 1887, American inventor William M. Meacham took up the same idea in Chicago.
In 1906, Italian engineer and inventor Enrico Forlanini carried out the first trials of the Idroplano, a 10-meter-long (33-foot) catamaran weighing just 1.62 tons and equipped with foils. Powered by a 70 HP engine, it reached 27 knots. He followed this up in 1911 with another 10-meter catamaran, this time powered by a 100 HP Fiat engine, which covered 18 nautical miles at an average speed of 40.5 knots.
Scottish-born Canadian American Alexander Graham Bell (inventor of the telephone) bought Forlanini’s patent and, together with his assistant Frederick W. Baldwin, improved the system, building several hydrofoil prototypes, and even set a world record with a speed of 71 knots. In 1907, the first truly flying powerboat was launched by American electrical engineer Peter Cooper Hewitt.

1938: The First Sailing Catamaran with Foils

Initially geared towards powerboats, the foiling system made its appearance on sailboats in 1938 with the Catafoil, a sailing catamaran with foils built by Englishmen Robert Rowe Gilruth and Bill Carl, taking their inspiration from the pioneers ...