Editing Hydrofoil (section)

=== Prototypes ===

The first evidence of a hydrofoil on a vessel appears on a British patent granted in 1869 to Emmanuel Denis Farcot, a Parisian. He claimed that "adapting to the sides and bottom of the vessel a series or inclined planes or wedge formed pieces, which as the vessel is driven forward will have the effect of lifting it in the water and reducing the draught.".<ref>{{Cite web|url=http://www.histarmar.com.ar/InfGral/Hidroalas/PrimerosHydrofoils.htm|title=Early Hydrofoils|website=histarmar.com.ar|access-date=2019-02-26}}</ref> Italian inventor [[Enrico Forlanini]] began work on hydrofoils in 1898 and used a "ladder" foil system. Forlanini obtained patents in Britain and the United States for his ideas and designs.<ref>{{cite web|url = http://www.foils.org/gallery/forlani.htm|title = Forlanini|publisher = International Hydrofoil Society|access-date = 22 January 2016|website = The Hydrofoil Resource Site|first = Malin|last = Dixon|url-status = dead|archive-url = https://web.archive.org/web/20170118154755/http://www.foils.org/gallery/forlani.htm|archive-date = 18 January 2017}}</ref><ref>[https://books.google.com/books?id=-t0DAAAAMBAJ&pg=PA927 "Italian Hydroplane of Curious Type."] ''Popular Mechanics'', December 1911, p. 927.</ref>

Between 1899 and 1901, British boat designer [[John Isaac Thornycroft|John Thornycroft]] worked on a series of models with a stepped hull and single bow foil. In 1909 his company built the full scale {{convert|22|ft|m|adj=on}} long boat, ''Miranda III''. Driven by a {{convert|60|hp|abbr=on}} engine, it rode on a bowfoil and flat stern. The subsequent ''Miranda IV'' was credited with a speed of {{convert|35|kn|km/h mph|abbr=on}}.<ref>{{cite web | title=Thornycroft Model Collection| url=http://www.hovercraft-museum.org/musthorn1.html | access-date=9 September 2009 |archive-url=https://web.archive.org/web/20090624185932/http://www.hovercraft-museum.org/musthorn1.html |archive-date=24 June 2009}}</ref>

[[Image:Bell HD-4.jpg|thumb|[[Alexander Graham Bell]]'s ''[[HD-4]]'' on a test run, c. 1919]]

In May 1904 a hydrofoil boat was described being tested on the [[River Seine]] "in the neighbourhood of [[Paris]]".<ref>The Principle of the Aeroplane Applied to the Boat, The Automotor Journal, 21 May 1904, p21</ref> This boat was designed by [[Charles de Lambert (aviator)|Comte de Lambert]].<ref>The Hydroplane or Gliding Boat, St James's Gazette, 24 May 1904, p16</ref> This had 5 variable pitch fins on the hull beneath the water so inclined that when the boat begins to move "the boat rises and the planes come to the surface" with the result that "it skims over the surface with little but the propellers beneath the surface". The boat had twin hulls 18-foot long connected by a single deck 9-foot wide, and was fitted with a 14HP [[De Dion-Bouton]] motor, the boat was reported to have reached 20&nbsp;mph. It was stated that "The boat running practically on its fins resembles an aeroplane".

A March 1906 [[Scientific American]] article by American hydrofoil pioneer William E. Meacham explained the basic principle of hydrofoils. [[Alexander Graham Bell]] considered the invention of the [[Hydroplane (boat)|hydroplane]] (now regarded as a distinct type, but also employing lift) a very significant achievement, and after reading the article began to sketch concepts of what is now called a hydrofoil boat. With his chief engineer [[Frederick W. Baldwin|Casey Baldwin]], Bell began hydrofoil experiments in the summer of 1908. Baldwin studied the work of the Italian inventor [[Enrico Forlanini]] and began testing models based on those designs, which led to the development of hydrofoil watercraft. During Bell's world tour of 1910–1911, Bell and Baldwin met with Forlanini in Italy, where they rode in his hydrofoil boat over [[Lake Maggiore]]. Baldwin described it as being as smooth as flying.

On returning to Bell's large laboratory at his [[Beinn Bhreagh, Nova Scotia|Beinn Bhreagh]] estate near [[Baddeck, Nova Scotia]], they experimented with a number of designs, culminating in Bell's ''[[HD-4]]''. Using [[Renault]] engines, a top speed of {{convert|87|km/h|kn mph|abbr=on}} was achieved, accelerating rapidly, taking waves without difficulty, steering well and showing good stability. Bell's report to the [[United States Navy]] permitted him to obtain two 260&nbsp;kW (350&nbsp;hp) engines. On 9 September 1919 the ''HD-4'' set a world marine speed record of {{convert|114|km/h|kn mph|abbr=on}}, which stood for two decades.<ref name="canada encyclopedia">{{Cite encyclopedia |title=Hydrofoil |url=http://www.thecanadianencyclopedia.com/articles/hydrofoil |archive-url=https://web.archive.org/web/20120504002603/http://www.thecanadianencyclopedia.com/articles/hydrofoil |url-status=dead |archive-date=4 May 2012 |publisher=Historica Canada |encyclopedia=The Canadian Encyclopedia}}</ref> A full-scale replica of the ''HD-4'' is viewable at the [[Alexander Graham Bell#Legacy and honors|Alexander Graham Bell National Historic Site]] museum in Baddeck, Nova Scotia.

In the early 1950s an English couple built the ''White Hawk'', a jet-powered hydrofoil water craft, in an attempt to beat the absolute water speed record.<ref>[https://books.google.com/books?id=8NsDAAAAMBAJ&dq=1954+Popular+Mechanics+January&pg=PA70 "Jet Hydrofoil Shoots At World Record"] ''Popular Mechanics'', August 1953, pp. 70-71</ref> However, in tests, ''White Hawk'' could barely top the record breaking speed of the 1919 ''HD-4''.  The designers had faced an engineering phenomenon that limits the top speed of even modern hydrofoils: [[cavitation]] disturbs the lift created by the foils as they move through the water at speed above {{convert|60|kn|km/h mph|abbr=on}}, bending the lifting foil.<ref>''The World Water Speed Record'' by Leo Villa and Kevin Desmond, 1976</ref>

[[File:Fully submerged hydrofoils self-stabilizing system.svg|thumb|A schematic illustration of self-stabilizing systems for fully submerged hydrofoils. Its computer gathers data for the boom position and current water level to determine the required flap position.]]