Editing Hydrofoil

{{Short description|Type of fast watercraft and the name of the technology it uses}}
{{For|other types of foil|Foil (fluid mechanics)}}
 
{{Use dmy dates|date=July 2021}}
A '''hydrofoil''' is a lifting surface, or [[foil (fluid mechanics)|foil]], that operates in water. They are similar in appearance and purpose to [[aerofoil]]s used by [[aeroplane]]s. [[Boat]]s that use hydrofoil technology are also simply termed hydrofoils. As a hydrofoil craft gains speed, the hydrofoils lift the boat's [[Hull (watercraft)|hull]] out of the water, decreasing [[Drag (physics)|drag]] and allowing greater speeds.

==Description==
The hydrofoil was created by Eric Walters. The hydrofoil usually consists of a [[wing]]like structure mounted on [[strut]]s below the [[hull (watercraft)|hull]], or across the keels of a [[catamaran]] in a variety of boats (see illustration). As a hydrofoil-equipped watercraft increases in speed, the hydrofoil elements below the hull(s) develop enough [[lift (force)|lift]] to raise the hull out of the water, which greatly reduces hull [[drag (physics)|drag]]. This provides a corresponding increase in [[speed]] and [[fuel efficiency]].

Wider adoption of hydrofoils is prevented by the increased complexity of building and maintaining them. Hydrofoils are generally prohibitively more expensive than conventional watercraft above a certain displacement, so most hydrofoil craft are relatively small, and are mainly used as high-speed passenger ferries, where the relatively high passenger fees can offset the high cost of the craft itself. However, the design is simple enough that there are many [[human-powered hydrofoil]] designs. Amateur experimentation and development of the concept is popular.<ref>{{cite AV media|url=https://www.youtube.com/results?search_query=hydrofoil+design&search=Search&gl=CA&hl=en|title=hydrofoil design - YouTube}}</ref>

==Hydrodynamic mechanics==
{{unreferenced section|date=March 2016}}
[[File:Hydrofoil types.svg|450px|thumb|The two types of hydrofoils: surface-piercing and fully submerged]]

Since air and water are governed by similar [[fluid dynamics|fluid equations]]—albeit with different levels of [[viscosity]], [[density]], and [[compressible flow|compressibility]]—the hydrofoil and [[airfoil]] (both types of [[foil (fluid mechanics)|foil]]) create [[lift (force)|lift]] in identical ways. The foil shape moves smoothly through the water, deflecting the flow downward, which, following the [[Euler equations (fluid dynamics)|Euler equations]], exerts an upward force on the foil.  This turning of the water creates higher pressure on the bottom of the foil and reduced pressure on the top. This pressure difference is accompanied by a velocity difference, via [[Bernoulli's principle]], so the resulting flow field about the foil has a higher average velocity on one side than the other.

When used as a lifting element on a hydrofoil boat, this upward force lifts the body of the vessel, decreasing drag and increasing speed. The lifting force eventually balances with the weight of the craft, reaching a point where the hydrofoil no longer lifts out of the water but remains in equilibrium. Since wave resistance and other impeding forces such as various types of [[drag (physics)]] on the hull are eliminated as the hull lifts clear, turbulence and drag act increasingly on the much smaller surface area of the hydrofoil, and decreasingly on the hull, creating a marked increase in speed.<ref>{{cite web
 | url =http://web.mit.edu/2.972/www/reports/hydrofoil/hydrofoil.html
 | title =Hydrofoils
 | last =Rosado
 | first =Tina
 | date =1999
 | website =Reports on How Things Work
 | publisher =Massachusetts Institute of Technology
 | access-date =11 December 2016
 }}</ref>

===Foil configurations===
Early hydrofoils used V-shaped foils. Hydrofoils of this type are known as "surface-piercing" since portions of the V-shape hydrofoils rise above the water surface when foilborne. Some modern hydrofoils use fully submerged inverted T-shape foils. Fully submerged hydrofoils are less subject to the effects of wave action, and, therefore, more stable at sea and more comfortable for crew and passengers. This type of configuration, however, is not self-stabilizing. The [[angle of attack]] on the hydrofoils must be adjusted continuously to changing conditions, a control process performed by sensors, a computer, and active surfaces.

== History ==
[[File:Forlanini Idroplano-Forlani Hydrofoil 1910.jpg|thumb|[[Enrico Forlanini|Forlanini's]] hydrofoil over [[Lake Maggiore]], 1906]]

=== 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.]]

=== First passenger boats ===

German engineer Hanns von Schertel worked on hydrofoils prior to and during [[World War II]] in [[Germany]]. After the war, the Russians captured Schertel's team. As Germany was not authorized to build fast boats, Schertel went to [[Switzerland]], where he established the Supramar company. In 1952, Supramar launched the first commercial hydrofoil, PT10 "Freccia d'Oro" (Golden Arrow), in Lake Maggiore, between Switzerland and [[Italy]]. The PT10 is of surface-piercing type, it can carry 32 passengers and travel at {{convert|35|kn|km/h mph}}. In 1968, the Bahraini born banker [[Hussain Najadi]] acquired the Supramar AG and expanded its operations into Japan, Hong Kong, Singapore, the UK, Norway and the US. [[General Dynamics]] of the United States became its licensee, and the Pentagon awarded its first R&D naval research project in the field of [[supercavitation]]. [[Hitachi]] Shipbuilding of Osaka, Japan, was another licensee of Supramar, as well as many leading ship owners and shipyards in the OECD countries.

From 1952 to 1971, Supramar designed many models of hydrofoils: PT20, PT50, PT75, PT100 and PT150. All are of surface-piercing type, except the PT150 combining a surface-piercing foil forward with a fully submerged foil in the aft location. Over 200 of Supramar's design were built, most of them by Rodriquez (headed at the time by Engineer Carlo Rodriquez in [[Sicily]], Italy.

During the same period the [[Soviet Union]] experimented extensively with hydrofoils, constructing hydrofoil river boats and [[ferries]] with streamlined designs during the cold war period and into the 1980s. Such vessels include the [[Raketa (hydrofoil)|Raketa]] (1957) type, followed by the larger [[Meteor (hydrofoil)|Meteor]] type and the smaller [[Voskhod (hydrofoil)|Voskhod]] type. One of the most successful Soviet designer/inventor in this area was [[Rostislav Alexeyev]], who some consider the 'father' of the modern hydrofoil due to his 1950s era high speed hydrofoil designs.{{Citation needed|date=August 2009}} Later, circa 1970s, Alexeyev combined his hydrofoil experience with the [[Ground effect in aircraft|surface effect]] principle to create the [[Ekranoplan]]. Extensive investment in this type of technology in the USSR resulted in the largest civil hydrofoil fleet in the world and the making of the Meteor type, the most successful hydrofoil in history, with more than 400 units built.

<gallery class="center" caption="Soviet civil hydrofoils" widths="180px" heights="120px">
Peterhof hydrofoil (18272163540).jpg|[[Voskhod (hydrofoil)|Voskhod]]
Meteor boat on Neva Bay.jpg|[[:ru:Метеор (теплоход)|Meteor]]
Raketa-185 on Khimki Reservoir 6-jun-2014 02.jpg|[[Raketa (hydrofoil)|Raketa]]
Polesye-1 (ship, 1986, Gomel, 7).jpg|[[:ru:Полесье (теплоход)|Polesye]]
Kizhi 06-2017 img30 Kometa-17 hydrofoil.jpg|[[:ru:Комета (теплоход)|Kometa]]
</gallery>

In 1961, [[SRI International]] issued a study on "The Economic Feasibility of Passenger Hydrofoil Craft in US Domestic and Foreign Commerce".<ref name="Feasibility">{{cite web |title = The Economic Feasibility of Passenger Hydrofoil Craft in U.S. Domestic and Foreign Commerce.|author = SRI International|author-link = SRI International|url = http://ntlsearch.bts.gov/tris/record/tris/00026416.html|year = 1961|access-date = 9 September 2009|archive-url = https://web.archive.org/web/20120301104231/http://ntlsearch.bts.gov/repository/record/tris/00026416.html|archive-date = 1 March 2012}}</ref> Commercial use of hydrofoils in the US first appeared in 1961 when two commuter vessels were commissioned by [[Harry Gale Nye, Jr.]]'s North American Hydrofoils to service the route from Atlantic Highlands, New Jersey to the financial district of Lower Manhattan.<ref>{{cite web| title=Enterprise|first = Malin | last= Dixon| url=http://www.foils.org/gallery/enterpr.htm| access-date=9 September 2009| url-status=dead| archive-url=https://web.archive.org/web/20100428050743/http://www.foils.org/gallery/enterpr.htm| archive-date=28 April 2010}}</ref>

==Military usage==

===Germany===
A 17-ton German craft ''VS-6 Hydrofoil'' was designed and constructed in 1940, completed in 1941 for use as a mine layer; it was tested in the [[Baltic Sea]], producing speeds of 47 knots. Tested against a standard [[E-boat]] over the next three years it performed well but was not brought into production. Being faster it could carry a higher payload and was capable of travelling over minefields but was prone to damage and noisier.<ref>{{cite book |title=Channel Islands Occupation Review No 34 |publisher=Channel Islands Occupation Society |date=2006}}</ref>

===Canada===
[[File:HMCS Bras d'Or 03.jpg|thumb|HMCS ''Bras d'Or'', a military concept hydrofoil.]]
In Canada during World War II, Baldwin worked on an experimental [[smoke screen|smoke laying]] hydrofoil (later called the Comox Torpedo) that was later superseded by other smoke-laying technology and an experimental target-towing hydrofoil. The forward two foil assemblies of what is believed to be the latter hydrofoil were salvaged in the mid-1960s from a derelict hulk in Baddeck, Nova Scotia by Colin MacGregor Stevens. These were donated to the Maritime Museum in Halifax, Nova Scotia.

The [[Canadian Forces Maritime Command|Canadian Armed Forces]] built and tested a number of hydrofoils (e.g., Baddeck and two vessels named ''Bras d'Or''), which culminated in the high-speed anti-submarine hydrofoil [[HMCS Bras d'Or (FHE 400)|HMCS ''Bras d'Or'']] in the late 1960s. However, the program was cancelled in the early 1970s due to a shift away from [[anti-submarine warfare]] by the Canadian military.  The ''Bras d'Or'' was a surface-piercing type that performed well during her trials, reaching a maximum speed of {{convert|63|kn|km/h}}.

===Soviet Union===
[[File:BTK pr.206M2.jpg|thumb|A Soviet [[Turya-class torpedo boat|Project 206M "Shtorm"]] patrol fast attack craft hydrofoil of the [[Cuban Navy]].]]
The USSR introduced several hydrofoil-based fast attack craft into [[Soviet Navy|their navy]], principally:
* [[Sarancha class missile boat|''Sarancha'' class missile boat]], a unique vessel built in the 1970s
* [[Turya class torpedo boat|''Turya'' class torpedo boat]], introduced in 1972 and still in service
* [[Matka class missile boat|''Matka'' class missile boat]], introduced in the 1980s and still in service
* [[Muravey class patrol boat|''Muravey'' class patrol boat]], introduced in the 1980s and still in service
* [[Project 664-class torpedo boat|Project 664]]

===United States===
[[File:Aerial port beam view of USS Aquila (PHM-4) underway US Navy DN-SC-87-07089.jpg|thumb|[[USS Aquila (PHM-4)|USS ''Aquila'']], a military hydrofoil. The T-shaped foils are visible just below the water.]]
The [[United States Navy|US Navy]] began experiments with hydrofoils in the mid-1950s by funding a sailing vessel that used hydrofoils to reach speeds in the 30&nbsp;mph range.<ref>[https://books.google.com/books?id=u-EDAAAAMBAJ&pg=PA136 "Sail Boat Stilts Boost Speed."] ''Popular Mechanics'', February 1956, p. 136.</ref> The [[Experimental Craft Hydrofoil No. 4 (XCH-4)|''XCH-4'']] (officially, ''Experimental Craft, Hydrofoil No. 4''), designed by [[William P. Carl]], exceeded speeds of {{convert|65|mph|kn km/h|abbr=on}} and was mistaken for a seaplane due to its shape.<ref>{{cite web|url=http://www.foils.org/index.html|title=XCH4|publisher=International Hydrofoil Society|access-date=8 August 2014|url-status=dead|archive-url=https://web.archive.org/web/20140819151056/http://foils.org/index.html|archive-date=19 August 2014}}</ref> ''Halobates'' was a 1957 US Navy prototype hydrofoil boat built by [[Miami Shipbuilding]]. <ref name="auto">{{Cite web|url=https://www.foils.org/wp-content/uploads/2017/09/MIAMI-97-2000-Copy-1.pdf|title=The Rise and Fall of Miami Shipbuilding  Corporation, by Robert Johnston, 14 Jul 03}}</ref>

The US Navy implemented a small number of combat hydrofoils, such as the [[Pegasus class hydrofoil|''Pegasus'' class]], from 1977 through 1993. These hydrofoils were fast and well armed.<ref name="JenkinsPegasus">{{cite web |author=George Jenkins | url=http://www.foils.org/phmhist.pdf | title=Patrol Combatant Missile (Hydrofoil): PHM History 1973–1995 | publisher=Foils.org | date=1 November 2000 | archive-url=https://web.archive.org/web/20170817075536/http://www.foils.org/phmhist.pdf | archive-date=2017-08-17 | access-date=2017-08-16 }}</ref>

===Italy===
[[File:Sparviero DN-ST-84-03940.jpg|thumb|right|Italian ''Sparviero'' class hydrofoil-missile NIBBIO P-421.]]
The [[Marina Militare|Italian Navy]] used six hydrofoils of the [[Sparviero class patrol boat|''Sparviero'' class]] starting in the late 1970s. These were armed with a 76&nbsp;mm gun and two missiles, and were capable of speeds up to {{convert|50|kn|km/h}}. Three similar boats were built for the [[Japan Maritime Self-Defense Force]].

==Sailing and sports==
{{main article|Sailing hydrofoil}}
[[File:AC72 New Zealand Aotearoa San Francisco 01.jpg|thumb|[[Team New Zealand]]'s AC72 at the 2013 America's Cup, San Francisco Bay.]]
Several editions of the [[America's Cup]] have been raced with foiling yachts. The 2013 and 2017 editions used the [[AC72]] and [[AC50]] classes of [[catamaran]] respectively, and the 2021 edition used the [[AC75|AC75 class]] of foiling monohulls with canting arms.

The French experimental sail-powered hydrofoil ''[[Hydroptère]]'' is the result of a research project that involves advanced engineering skills and technologies. In September 2009, the ''Hydroptère'' set new sailcraft world speed records in the 500&nbsp;m category, with a speed of {{convert|51.36|knot|km/h}} and in the {{convert|1|nmi|m|round=0.5|comma=5}} category with a speed of {{convert|50.17|knot|km/h}}.<ref>{{Cite web|url=http://www.sailspeedrecords.com/index.php?option=com_content&view=article&id=104:wssr-newsletter-no-177-hydroptere-world-records-230909&catid=2:news&Itemid=5|title=World Sailing Speed Record Council|website=sailspeedrecords.com}}</ref><ref>{{Cite web|url=http://www.sailspeedrecords.com/index.php?option=com_content&view=article&id=105:wssr-newsletter-no-178-hydroptere-nautical-mile-201109&catid=2:news&Itemid=5|title=World Sailing Speed Record Council|website=sailspeedrecords.com}}</ref>

The 500&nbsp;m speed record for sailboats is currently held by the ''[[Vestas Sailrocket]]'', an exotic design which operates in effect as a hydrofoil.<ref>{{cite magazine |last1=Fisher |first1=Adam |title=How a Boat-Plane Hybrid Shattered the Sound Barrier of Sailing |url=https://www.wired.com/2013/01/ff-paul-larsen-sailrocket/ |magazine=Wired |access-date=10 May 2021}}</ref>

Another trimaran sailboat is the Windrider Rave.<ref>{{cite web | title=Windrider Wave | author=Windrider | url=http://www.windrider.com/rave.shtml | access-date=7 September 2009 | archive-date=9 May 2007 | archive-url=https://web.archive.org/web/20070509083641/http://windrider.com/rave.shtml | url-status=dead }}</ref> The Rave is a commercially available {{convert|17|ft|m|adj=on}}, two person, hydrofoil trimaran, capable of reaching speeds of {{convert|40|kn|km/h|abbr=on}}.  The boat was designed by Jim Brown.

The [[Moth (dinghy)|Moth dinghy]] has evolved into some radical foil configurations.<ref>{{cite news|url=https://www.irishtimes.com/sport/other-sports/gliding-on-top-of-the-water-is-still-sailing-but-not-as-we-know-it-1.1533581|newspaper=The Irish Times|date=September 20, 2013|first=David|last=Branigan|title=Gliding on top of the water is still sailing but not as we know it}}</ref>

[[Hobie Cat|Hobie Sailboats]] produced a production foiling [[trimaran]], the Hobie Trifoiler, the fastest production sailboat. Trifoilers have clocked speeds upward of thirty knots.

A new kayak design, called [[Flyak]], has hydrofoils that lift the kayak enough to significantly reduce drag, allowing speeds of up to {{convert|27|km/h|0|abbr=on}}. Some [[Surfing|surfers]] have developed surfboards with hydrofoils called [[foilboard]]s, specifically aimed at surfing big waves further out to sea.<ref>{{cite web  |title= Laird Hamilton: A Surfermag.com exclusive interview |author= Scott Bass |work= [[Surfer (magazine)|Surfer Magazine]] |year= 2009 |url= http://www.surfermag.com/features/onlineexclusives/lairdintrvu/ |access-date=2 December 2010}}
</ref>

Quadrofoil Q2 is a two-seater, four-foiled hydrofoil electrical leisure watercraft. Its initial design was set in 2012 and it has been available commercially since the end of 2016. Powered by a 5.2-kWh lithium-ion battery pack and propelled by a 5.5&nbsp;kW motor, it reaches the top speed of 40&nbsp;km/h and has 80&nbsp;km of range.<ref name="Quadrofoil1">{{cite web |author=Stu Robarts | url=http://newatlas.com/quadrofoil-q2-electric-hydrofoil/46973/?li_source=LI&li_medium=default-widget | title=Electric hydrofoil finally ready to skim the waves | publisher=New Atlas | date=15 December 2016 | archive-url=https://web.archive.org/web/20170817021150/http://newatlas.com/quadrofoil-q2-electric-hydrofoil/46973/?li_source=LI&li_medium=default-widget | archive-date=2017-08-17 | access-date=2017-08-16 }}</ref><ref name="Quadrofoil3">{{cite web |author=Fred Lambert |authorlink=Fred Lambert| url=https://electrek.co/2016/12/22/all-electric-quadrofoil-boat/ | title=All-electric Quadrofoil will soon allow you to fly on water – production is ready, says CEO | work= [[Electrek]] | date=22 December 2016 | archive-url=https://web.archive.org/web/20170817073151/https://electrek.co/2016/12/22/all-electric-quadrofoil-boat/ | archive-date=2017-08-17 | access-date=2017-08-16 }}</ref>

The Manta5 Hydrofoiler XE-1 is a Hydrofoil E-bike, designed and built in [[New Zealand]] that has since been available commercially for pre-order since late 2017.<ref>{{cite web | title= Hydrofoil water bike to launch before Christmas | year= 2017 | url= https://www.stuff.co.nz/business/innovation/90820686/Hydrofoil-water-bike-to-launch-before-Christmas }}</ref> Propelled by a 400 watt motor, it can reach speeds exceeding 14&nbsp;km/h with a weight of 22&nbsp;kg. A single charge of the battery lasts an hour for a rider weighing 85&nbsp;kg.<ref>{{cite web | title = Ride on water: Pre-sale reservations now available for Manta5 hydrofoiling e-bike | year= 2018| url= https://newatlas.com/manta5-hydrofoil-ebike-ride-on-water/55611/ }}</ref>

Candela, a Swedish company, is producing a recreational hydrofoil powerboat, making strong claims for efficiency, performance, and range.<ref>{{cite web |last1=Toll |first1=Micah |title=Watch the world's first electric hydrofoil boat in action |url=https://electrek.co/2020/08/25/worlds-first-electric-hydrofoil-boat-candela-7/ |website=Elektrek |date=25 August 2020 |access-date=10 May 2021}}</ref>

Hydrofoils are now widely used with [[kitesurfing]],<ref>{{cite web|url=https://www.surfertoday.com/kiteboarding/the-bright-and-dark-sides-of-kite-foilboarding|title= The bright and dark sides of kite foilboarding |date=January 28, 2014|work=Surfer Today}}</ref> that is traction kites over water. Hydrofoils are a new trend in [[windsurfing]]<ref>{{cite web|url=https://windfoilzone.com/windfoil-vs-windsurfing/|title=Windfoiling vs Windsurfing – Is Foil is the Future?|first=Romain|last=Jourdan|date=21 January 2021|publisher=Wind Foil Zone|access-date=11 April 2022|archive-date=21 April 2021|archive-url=https://web.archive.org/web/20210421203638/https://windfoilzone.com/windfoil-vs-windsurfing/|url-status=dead}}</ref>  - including the new Summer Olympic class, the [[IQFoil]],<ref>{{cite news |last1=Morgan |first1=Liam |title=World Sailing Council approve Starboard iFoil as windsurfing equipment at Paris 2024 |url=https://www.insidethegames.biz/articles/1086570/starboard-ifoil-approved-paris-2024 |accessdate=21 August 2020 |work=[[Inside the Games]] |date=1 November 2019}}</ref>  and more recently with [[Wing foiling]],  which are essentially a kite with no strings, or a hand-held sail.<ref>{{cite web|url=https://www.ft.com/content/87e259cc-36b0-4583-b3b4-dfea0883eb41 |archive-url=https://ghostarchive.org/archive/20221210/https://www.ft.com/content/87e259cc-36b0-4583-b3b4-dfea0883eb41 |archive-date=10 December 2022 |url-access=subscription|work=Financial Times|title=The only way is up: the irresistible rise of wing foiling|first=Chris|last=Clothier|date=June 18, 2021}}</ref>

[[File:Draagvleugelboot Karla.jpg|thumb|Ukrainian-built [[Voskhod (hydrofoil)|Voskhod]] on the [[noordzeekanaal|North Sea Canal]], the [[Netherlands]]]]
[[File:20091105-TurboJET Urzela.jpg|thumb|[[TurboJET]]'s ''Urzela'' JetFoil on [[West Lamma Channel]], [[Hong Kong]]]]
[[File:20091109-TurboJET Barca.jpg|thumb|[[TurboJET]]'s ''Barca'' Foilcat]]

== Modern passenger boats ==
[[File:MV Flying Poseidon (1982) and Bodrum Lines Kometas at Rhodes with MV Costa Fortuna 11am 5-8-2011.jpg|thumb|''Flying Poseidon'' (built 1982<ref>{{cite web|url=http://www.marinetraffic.com/ais/shipdetails.aspx?MMSI=376308000|archive-url=https://archive.today/20131009030444/http://www.marinetraffic.com/ais/shipdetails.aspx?MMSI=376308000|url-status=dead|archive-date=2013-10-09|title=Flying Poseidon|work=Marinetraffic.com}}</ref>) had just berthed at [[Rhodes]] from [[Fethiye]] when the sister ''Kometas'' hydrofoil<ref>{{cite web|url=http://www.hydrofoils.org/HGal/hgal.htm|title=Russian Hydrofoil Page}}</ref> from [[Bodrum]] also arrived from [[Turkey]] in 2011.]]

Soviet-built [[Voskhod (hydrofoil)|Voskhods]] are one of the most successful passenger hydrofoil designs. Manufactured in Soviet and later Ukrainian Crimea, they are in service in more than 20 countries. The most recent model, [[Voskhod (hydrofoil)|Voskhod-2M FFF]], also known as Eurofoil, was built in [[Feodosiya]] for the Dutch public transport operator [[Connexxion]].<ref>{{cite web|title=Fast Flying Ferry |author=Connexxion |author-link=Connexxion |url=http://www.connexxion.nl/over_water/23/fast_flying_ferry/239 |access-date=9 September 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090823051004/http://www.connexxion.nl/over_water/23/fast_flying_ferry/239/ |archive-date=23 August 2009 }}</ref>

[[File:Type "Kometa 120M" hydrofoil in Sevastopol, Crimea - 2020.jpg|thumb|The first Kometa 120M, named Chaika (Seagull) after [[Valentina Tereshkova]]'s callsign, moored in [[Sevastopol]]]]
Mid-2010s saw a Russian governmental program aimed at restoring passenger hydrofoil production. The {{ill|Kometa 120M|ru|Комета 120М}},  based on the earlier {{ill|Kometa|ru|Комета (теплоход)}}, Kolhida and Katran models, became the first to enter production,<ref>{{cite web |url=https://vm.ru/technology/550718-kometa-vzyala-kurs-na-poluostrov |title=Комета взяла курс на полуостров |trans-title=Kometa has set course for the peninsula |language=Russian |website=vm.ru |publisher=Вечерняя Москва|access-date=August 10, 2021}}</ref> initially on {{ill|Vympel (Rybinsk)|lt=Vympel|ru|Вымпел (судостроительный завод)}} factory in Rybinsk, and later on [[More (Feodosiya)|More]] shipyard in Feodosiya.<ref>{{cite web |url=https://tass.ru/obschestvo/7550113 |title=В Крыму приступили к постройке двух скоростных "Комет" для пассажирских перевозок |trans-title=Production of two high-speed "Komets" has started in Crimea |language=Russian |website=tass.ru |publisher=TASS|access-date=August 10, 2021}}</ref> Since 2018, the ships are running Sevastopol-Yalta and Sochi-Gelenzhik-Novorossiysk, with a Sevastopol-Sochi connection in the immediate plans in 2021.<ref>{{cite web |url=https://www.korabel.ru/news/comments/sochi_i_sevastopol_svyazhut_morskie_passazhirskie_komety.html |title=Сочи и Севастополь свяжут морские пассажирские "Кометы" |trans-title=Sea-going passenger "Komets" will link Sochi and Sevastopol|language=Russian |publisher=korabel.ru |access-date=August 10, 2021}}</ref> At the same time, the [[Alekseyev Central Hydrofoil Design Bureau|Alekseyev Bureau]] began building lighter, smaller {{ill|Valday 45R|ru|Валдай 45Р}} hydrofoils, based on a widely successful {{ill|Polesye (hydrofoil)|lt=Polesye|ru|Полесье_(теплоход)}} model, at its own plant in Nizhny Novgorod,<ref>{{cite web |url=https://www.korabel.ru/news/comments/valday_45r_prevzoshel_ozhidaniya_sozdateley.html |title="Валдай 45Р" превзошел ожидания создателей |trans-title="Valday 45R" has surpassed its creators' expectations |language=Russian |publisher=korabel.ru |access-date=August 10, 2021}}</ref> the relatively shallow-draft boats used on the Ob and the Volga. The {{ill|Meteor 120R|ru|Метеор 120Р}}, a development of the {{ill|Meteor (hydrofoil)|lt=Meteor|ru|Метеор (теплоход)}}, became the Valday's larger sibling, the first ship launched in Nizhny Novgorod in August 2021.<ref>{{cite web |url=http://www.morvesti.ru/news/1679/90897/ |title=Первый "Метеор 120Р" нового поколения спустили на воду в Нижегородской области |trans-title=The first new-generation «Meteor 120R» has been launched in Nizhny Novgorod oblast |language=Russian |website=morvesti.ru |publisher=Морские вести России |access-date=August 10, 2021}}</ref>

The [[Boeing 929]] is widely used in [[Asia]] for passenger services, between [[Hong Kong]] and [[Macau]] and between the many islands of [[Japan]], also on the [[Korean peninsula]]. The main user is Hong Kong private corp.

=== Current operation ===
{{More citations needed section|date=September 2022}}
Current operators of hydrofoils include:

* [[TurboJET]] service, which speeds passengers across the [[Pearl River Delta]] between [[Hong Kong–Macau Ferry Terminal|Hong Kong]] and [[Outer Harbour Ferry Terminal|Macau]] in less than an hour, with an average speed of 45 knots (83&nbsp;km/h), mainly using [[Boeing]]'s [[Boeing Jetfoil|Jetfoil]]. Also services [[Fuyong Ferry Terminal|Shenzhen]], [[Nansha Ferry Port|Panyu (Nansha)]] and [[China Ferry Terminal|Kowloon]]. Operated by Shun Tak-China Travel Ship Management Limited.
* [[Voskhod (hydrofoil)|Voskhod]] and ''Polesye'' service between [[Tulcea]] and [[Sulina]] on the [[Danube]].
* ''Meteor'' and ''Polesye'' service in [[Poland]] between [[Szczecin]] and [[Świnoujście]].
* ''Cometa'' service between [[Nizhneangarsk]] and [[Irkutsk]] on [[Lake Baikal]].
* ''Cometa'' service between [[Vladivostok]] and [[Slavyanka, Primorsky Krai|Slavyanka]].
* ''Polesye'' service between [[Mozyr]] and [[Turaŭ|Turov]] on the [[Pripyat River]] ([[Belarus]]).
* ''Meteor'' service between [[Saint Petersburg]], [[Russia]] and the [[Peterhof Palace]], a summer palace of Russian tsars.

[[File:Lake Ladoga. Valaam. Meteor hydrofoil P7170383 2200.jpg|thumb|Hydrofoil high-speed boat Meteor on [[Lake Ladoga]], [[Russia]].]]
[[File:Hydrofoil near Piraeus.JPG|thumb|Passenger hydrofoil ''Flying Dolphin Zeus'' moving at high speed near [[Piraeus]], [[Greece]].]]

* ''Meteor'' service between [[Saint Petersburg]], [[Russia]] and the [[Kronstadt]], a strongly fortified Russian seaport town, located on Kotlin Island, near the head of the Gulf of Finland. It lies thirty kilometers west of Saint Petersburg. Since 2012 replaced by a catamaran ''Mercury''.
* ''Meteor'', ''Raketa'' and ''Voskhod'' hydrofoil types operate all over [[Volga]], [[Don River (Russia)|Don]] and [[Kama River]]s in [[Russia]]. Also the [[Lena River]] and [[Amur River]].
* ''Meteor'' hydrofoils are operated by a number of tour operators in [[Croatia]], mostly for packaged tours, but there are also some scheduled services to islands in Adriatic.
* Hydrofoils are regularly operated on the three major Italian lakes by branches of the [[Ministry of Infrastructure and Transport (Italy)|Ministry of Infrastructure and Transport]]: ''[[Navigazione Lago Maggiore]]'' services routes on [[Lake Maggiore]] between [[Locarno]] and [[Arona, Piedmont|Arona]], ''[[Navigazione Lago di Como]]'' services routes on [[Lake Como]], and ''[[Navigazione Lago di Garda]]'' services routes on [[Lake Garda]]. Three units of the Rodriguez RHS150 type operate on each lake, for a total of nine hydrofoils.
* Former Russian hydrofoils are used in southern Italy for connection with islands of [[Lazio]] and [[Campania]]. SNAV has five RHS200, RHS160 and RHS150 used in the connections between [[Naples]] and the islands of [[Capri]] and [[Ischia]].
* A regular hydrofoil service runs from [[Istanbul]] to [[Yalova]].
* [[Hellenic Seaways]] operate their Flying Dolphins service over many routes in the [[Aegean Sea|Aegean]], between the [[Cyclades]], [[Saronic Gulf]] islands such as Aegina and Poros, and [[Athens]].
* ''Meteor'' (2), ''Polesye'' (4) and ''Voskhod'' (3) hydrofoil types operate in [[Hungary]]. MAHART PassNave Ltd. operates scheduled hydrofoil liners between [[Budapest]], [[Bratislava]] and [[Vienna]], inland liners between Budapest and the [[Danube Bend]], and theme cruises to Komárom, Solt, Kalocsa and Mohács.
* "Kometa" Flying Dolphin services are currently operated by Joy Cruises between [[Corfu]] and [[Paxos (island)|Paxos]]. They run from [[Corfu (city)|Corfu Port]] to [[Gaios]] using two hydrofoils: ''Ilida'' and ''Ilida II''. The company operates also an international service from Corfu to Saranda (Albania) using the hydrofoil ''Ilida Dolphin'' of the same type.
* "Kometa" type hydrofoils (registered in Albania) are operated by Ionian Cruises and Finikas Lines between Saranda and Corfu.
* Russian hydrofoils of the ''Kometa'' type operated on the [[Bulgarian Black Sea Coast]] connecting [[Varna, Bulgaria|Varna]], [[Nesebar]], [[Burgas]], [[Sozopol]], [[Primorsko]], and [[Tsarevo]], and ''Raketa'' and ''Meteor'' models served the Bulgarian [[Danube]] ports between [[Rousse]] and [[Vidin]]. Both services were discontinued in the 1990s. In 2011 the service reopened between Varna, Nesebar, Burgas and Sozopol, operated by Bulgarian Hydrofoils Ltd.
* Vietnamese ''Greenline Company'' operates hourly shuttle service between [[Ho Chi Minh City]], [[Vung Tau]] and [[Con Dao]] island. Hydrofoil lines using the Russian-built Meteor type also connect [[Hai Phong]], [[Ha Long]] and [[Mong Cai]] in North Vietnam, [[Phan Thiet]] and [[Phu Quy Island]] and between [[Rach Gia]] and [[Phu Quoc Island]] in the South.
*The service between [[Busan]], [[South Korea]] and [[Fukuoka, Fukuoka|Fukuoka]], [[Japan]] is operated by two companies. Japanese [[:ja:JR九州高速船|JR Kyūshū Jet Ferry]] operates ''[[Beetle (JR Kyushu)|Beetle]]'' five times a day. Korean [[Miraejet]] operates ''[[Kobee]]'' three to four times a day. All of their fleets are [[Boeing Jetfoil|Boeing 929]].
*As of February 2008, all of the commercial lines in Japan use [[Boeing Jetfoil|Boeing 929]]. The routes include:
**[[:ja:佐渡汽船|Sado Kisen]] operates the route between [[Sado, Niigata|Sado]] and [[Niigata, Niigata|Niigata]].
**[[Tōkai Kisen]] operates ''Seven Islands'', running between [[Tokyo]] and [[Izu Islands]], via [[Tateyama, Chiba|Tateyama]] or [[Yokosuka, Kanagawa|Yokosuka]]. The destinations include [[Izu Ōshima]], [[Toshima Island|Toshima]], [[Niijima]], [[Shikinejima]], and [[Kozushima|Kōzushima]]. The same ship also links [[Atami, Shizuoka|Atami]] and Izu Ōshima.
**[[:ja:九州郵船|Kyūshū Yūsen]] operates the route between [[Fukuoka, Fukuoka|Fukuoka]], [[Iki Island|Iki]], and the two ports of [[Tsushima Island|Tsushima]].
**[[:ja:九州商船|Kyūshū Shōsen]] operates the route between [[Nagasaki, Nagasaki|Nagasaki]] and the two of [[Gotō Islands]], namely [[:ja:福江島|Fukuejima]] and [[Nakadorijima|Nakadōrijima]].
**[[:ja:鹿児島商船|Kagoshima Shōsen]] and [[:ja:コスモライン (鹿児島県)|Cosmo Line]] operate the various routes between [[Kagoshima, Kagoshima|Kagoshima]] and [[Tanegashima]] or [[Yakushima]].
* In 2012, Agriculture, Fisheries and Conservation Department (AFCD) in [[Hong Kong]] leased a 12-meter HAWC (Hydrofoil Assisted Water Craft), a [[catamaran]], to patrol the [[Hong Kong UNESCO Global Geopark]] in the [[Sai Kung District|Sai Kung]] Volcanic Rock Region.
* In 2017, [[Voskhod (hydrofoil)|Voskhod]] boat began operating on 2 lines in [[Ukraine]]: [[Nova Kakhovka]]-[[Kherson]]-[[Hola Prystan]], [[Mykolaiv]]-[[Kinburn Spit]], [[Ochakiv]]-[[Kinburn Spit]].<ref>[https://dnepr.news/news/dnepr-otnyne-mozhno-preodolet-na-rakete Днепр отныне можно преодолеть на ракете]. - dnepr.news</ref>
* In July 2018, the new generation [[Kometa 120M]] boat has started operation on the busy [[Sevastopol]]-[[Yalta]] route in [[Crimea]], with the plans to add two more and possible other routes in 2019.
* In Italy hydrofoils have been used for commercial connections since 1956, by the Rodriguez shipyards and the [[SNAV]] company. Currently, the main hydrofoil operator in Italy is Liberty Lines,<ref>[https://www.libertylines.it/compagnia/la-nostra-flotta/]</ref> which operates connections between the smaller Sicilian islands with Sicily and Calabria and between Trieste and some towns on the Croatian coast. SNAV operates connections between Naples and the smaller Campanian islands and - in the summer period - between Naples and the Aeolian Islands.

=== Discontinued operations ===
* Until 31 December 2013, Fast Flying Ferries operated by [[Connexxion]] provided a regular [[public transport]] service over the [[North Sea Canal]] between [[Amsterdam Centraal|Amsterdam Central Station]] and [[Velsen|Velsen-Zuid]] in the [[Netherlands]], using [[Voskhod (hydrofoil)|Voskhod]] 2M hydrofoils. It was stopped due to a new [[speed limit]].<ref>{{cite web |title=Fast Flying Ferry ends in 2014 |url=http://water.connexxion.nl/diensten/602/fast-flying-ferry-stopt-in-2014/2728 |website=[[Connexxion]] |language=Dutch |date=1 March 2013 |access-date=2 July 2013 |archive-url=https://web.archive.org/web/20130721083912/http://water.connexxion.nl/diensten/602/fast-flying-ferry-stopt-in-2014/2728 |archive-date=21 July 2013 |url-status=dead |df=dmy-all }}</ref>
* Between 1981 and 1990, [[Transmediterranea]] operated a service of hydrofoils connecting [[Ceuta]] and [[Algeciras]] in the Strait of Gibraltar. The crossing took half an hour, in comparison to the hour and a half of conventional ferries. Due to the common extreme winds and storms that take place in winter in the Strait of Gibraltar, the service was replaced in 1990 by catamarans, which were also able to carry cars. At the peak of the year, in summer, there was a service every half an hour in each direction. This high-speed connection had a big impact on the development of Ceuta, facilitating one-day business trips to mainland Spain.
* Between 1964 and 1991 the [[Sydney hydrofoils]] operated on [[Port Jackson|Sydney Harbour]] between [[Circular Quay]] and [[Manly, New South Wales|Manly]].
* Between 1969 and 1998 [[Red Funnel]] operated between [[Southampton]] and [[Cowes|Cowes, Isle of Wight]].<ref>{{Cite web|title=Red Funnel Hydrofoil Passenger Ferry|url=https://www.wightpedia.org.uk/detail2.php?id=red-funnel-hydrofoil-passenger-ferry|access-date=2021-02-05}}</ref>
* During the 1970s and 1980s there were frequent services between [[Belgrade]] and [[Tekija (Kladovo)|Tekija]] in [[Iron Gates|Đerdap gorge]]. The distance of {{convert|220|km|nmi mi|abbr=on}} was covered in 3 hours and 30 minutes downstream and 4 hours upstream.<ref>{{cite web | title=Beogradske priče: Gliserima do Đerdapa| author=Večernje novosti| author-link=Večernje novosti| url=http://www.novosti.rs/vesti/beograd.74.html:575041-Beogradske-price-Gliserima-do-Djerdapa | access-date=6 November 2015}}</ref>
* Between 1980 and 1981, [[British and Irish Steam Packet Company|B+I Line]] operated a [[Boeing 929]] jetfoil, named ''Cú Na Mara'' (Hound of the Sea), between Liverpool and Dublin. The service was not successful and was discontinued at the end of the 1981 season.<ref>{{Cite web|url=http://www.irishships.com/a_history_of_roll_on.htm|title=A History of Roll on|date=2006-03-19|website=archive.ph|access-date=2019-11-04|archive-date=19 March 2006|archive-url=https://archive.today/20060319220350/http://www.irishships.com/a_history_of_roll_on.htm|url-status=dead}}</ref>
* Between the 1960s and 1985 there were hydrofoils going between Malmö, Sweden and Copenhagen, Denmark. They were retired and exchanged for catamarans. The service  got cancelled when the Öresund Bridge got built in the early 2000s.
* [[Condor Ferries]] operated six hydrofoil ferries over a 29-year period between the [[Channel Islands]], the south coast of England and [[Saint-Malo]] in France.
* Following the restoration of [[Estonia]]n independence in the 1990s, the regular ferry service between [[Helsinki]] and [[Tallinn]] was augmented by Soviet built hydrofoils during the summer season in periods of good weather. The higher speed service competed with the traditional [[Roll-on/roll-off|ro-ro ferries]] but allowed easy day trips for pedestrian travellers. They were ultimately replaced with high-speed catamarans that could also carry vehicles and have better seaworthiness; however, the latter ceased operations as the operator filed for bankruptcy in May 2018.<ref>{{Cite web|url=https://news.err.ee/834522/linda-line-declared-bankrupt-by-court|title=Linda Line declared bankrupt by court|date=25 May 2018|website=ERR}}</ref>

== See also ==
{{Div col |colwidth=26em}}
* [[Boeing hydrofoils]]
* ''[[Disco Volante (ship)|Disco Volante]]''
* [[Flyak]] &ndash; a hydrofoil kayak
* [[Foilboard]]
* ''[[The Hydrofoil Mystery]]'' &ndash; historical fiction
* [[Hydroplane (boat)|Hydroplane]], a different application of lift to the hull itself
* [[Planing (sailing)]]
* ''[[Raketa (hydrofoil)|Raketa]]''
* [[Riverboat]]
* [[Sailing hydrofoil]]
* [[Sit-down hydrofoil]]
* [[Supercavitation]]
* [[Trampofoil]] &ndash; a one-person human-powered hydrofoil
* ''[[Voskhod (hydrofoil)|Voskhod]]''
* [[LISA Akoya]] &ndash; amphibious plane with hydrofoil assisted takeoff
{{Div col end}}

==References==
{{Reflist|30em}}

==External links==
{{wiktionary|hydrofoil}}
{{commons category|Hydrofoils}}
* [http://foils.org The International Hydrofoil Society]
* [http://www.hysucraft.com Fast CC Hydrofoil design by Prof. KG Hoppe, inventor of HYSUCAT technology patented by University of Stellenbosch, S.A.]
* [https://hyfoilmarine.com/ HYFOIL Marine has cooperative technology agreements with Prof. KG Hoppe]
* [http://www.hawctech.com Hydrofoil Assisted Water Craft employing HYSUCAT and HYSUWAC patents in their projects and vessels currently in operation]
* [http://www.hydrofoils.ch Swiss experimental hydrofoils]
* [https://web.archive.org/web/20100605014428/http://hyraii.ethz.ch/ HyRaii - Hydrofoil Sailboat, Student Project ETH Zurich]

{{Public transport|state=collapsed}}

{{Authority control}}

[[Category:Hydrofoils|*]]
[[Category:Nautical terminology]]
[[Category:English inventions]]
[[Category:Vehicles introduced in 1906]]