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75ft sailing hydrofoil monohull class developed for the 2021 America's Cup

Top 3 AC75 related articles

Ineos Team UK AC75
Year2017 -
No. built8 launched
Roleinshore racing
Crew11 + 1 optional guest
Boat weight6,450 kg (14,220 lb) lightship
7,600 kg (16,800 lb) loaded
Draft5.00 m (16 ft)
TypeFoiling Monohull
LOA22.86 m (75 ft)
LOH20.70 m (68 ft)
Beam5.00 m (16 ft)
Hull appendages
Generaltopside-mounted ballasted canting T-wing foils
Ballastset in foils
Rudder(s)centerline T-wing rudder
Rig typebermuda sloop
Mast length26.50 m (87 ft)
Generaltwo semi-battened mainsail skins, one headsail skin
Mainsail area145 m2 (1,560 sq ft)
Jib/genoa area90 m2 (970 sq ft)
Spinnaker area200 m2 (2,200 sq ft)

The AC75 (America's Cup 75) is a sailing class, governing the construction and operation of the yachts to be used in the 2021 America's Cup. The 23 m (75 ft) monohulls feature sailing hydrofoils mounted on topside longitudinal drums, a soft wingsail,[1] and no keel.[2]

AC75 Intro articles: 1

The rule

Following the 2017 America's Cup, the winning club Royal New Zealand Yacht Squadron accepted a notice of challenge from Circolo della Vela Sicilia that stipulated a monohull in the ship's particulars. Conceptual graphics of a monohull with soft sails and topside canting hydrofoils were released on 21 November 2017, and the first draft of the class rule was published by the defender and the challenger of record on 29 March 2018.[3] The return to monohulls with soft sails after three America's Cups on multihulls with wingsails is reminiscent of earlier America's Cup classes and seaworthy traditions, but the rule includes hydrofoils to attract high performance crews and large TV audiences.[4]

Under the protocol, each competing club may build two yachts, but two-boat testing is not allowed except during the PRADA Christmas Cup on December 17-20 2020 and for the defenders during the PRADA Cup January 15 - February 22 2021. In order to reduce design and testing costs of the class' unique features, the rule specifies foil controlling systems all manufactured by the defending club's team and foil arms all manufactured by the Challenger of Record's builder Persico Group.

AC75 The rule articles: 6

The boats

club team yacht name christening date builder notes
 Royal New Zealand Yacht Squadron Emirates Team New Zealand Te Aihe 6 September 2019 ETNZ test boat[5]
 New York Yacht Club American Magic Defiant 14 September 2019 American Magic test boat[6]
 Circolo della Vela Sicilia Luna Rossa Prada Pirelli Luna Rossa 2 October 2019 Persico Group test boat[7]
 Royal Yacht Squadron INEOS Team UK Britannia 4 October 2019 Carrington Boats test boat[8]
 New York Yacht Club American Magic Patriot 16 October 2020 American Magic race boat[9][10]
 Royal Yacht Squadron INEOS Team UK Britannia II 17 October 2020 Carrington Boats race boat[11]
 Circolo della Vela Sicilia Luna Rossa Prada Pirelli Luna Rossa 20 October 2020 Persico Group race boat[12]
 Royal New Zealand Yacht Squadron Emirates Team New Zealand Te Rehutai 18 November 2020 ETNZ race boat[13]

The visible differences between designs have been commented by most of the yachtbuilding community and the specialized press as each of the boats were launched.[14]


Speeds of 50 kn (93 km/h; 58 mph) have been claimed based on computer simulations.[15]

Notable high speeds actually recorded on the water have been:

  • 49.1 kn (90.9 km/h; 56.5 mph) by Te Rehutai (in 15 and 19 kn (28 and 35 km/h; 17 and 22 mph)) on December 17, 2020.[16]
  • 50.25 kn (93.06 km/h; 57.83 mph) by Britannia during day 4 of the Prada Cup January 23, 2021.
  • 53.31 kn (98.73 km/h; 61.35 mph) by Patriot (American Magic) during day 1 of the Prada Cup Semifinals (in breeze gusting up to 22 kn (41 km/h; 25 mph)) on January 29, 2021.[17]

Patent claim

In October 2020 patent infringement was claimed in New Zealand regarding the canting foil system used in the boats that have been produced. Team New Zealand said it had already rejected the claim because its system did not infringe any patent.[18][19]

See also


  1. ^ "The Sails of the America's Cup". Sailing World.
  2. ^ Hillary Noble (5 April 2018), America's Cup designer spotlight, North Sails
  3. ^ AC75 class rule version 1.1, americascup.com, 29 June 2018
  4. ^ Bernie Wilson (21 November 2017), Team New Zealand unveils radical foiling monohull, Associated Press
  5. ^ Team New Zealand launch their first AC75
  6. ^ A first flight and a name
  7. ^ 'Luna Rossa', the new flying monohull
  8. ^ Ineos Team UK name their first AC75 'Britannia'
  9. ^ Patriot christened and launched
  10. ^ Chase boats alongside also providing flotation, by tying themselves up to attachment points on Patriot.
  11. ^ INEOS TEAM UK christen 'Britannia'
  12. ^ Luna Rossa launches its second AC75
  13. ^ Emirates Team New Zealand launch Te Rehutai
  14. ^ Matthew Sheahan (23 October 2020), Challenger Revelations, planetsail.org
  15. ^ "American Magic shines as racing begins". Scuttlebutt Sailing News. 17 December 2020. Archived from the original on 27 December 2020. Retrieved 27 December 2020.
  16. ^ "How fast can Team New Zealand's AC75 go? Grant Dalton explains the new boat's design". TVNZ. 5 September 2019. Archived from the original on 15 January 2020. Retrieved 3 November 2020.
  17. ^ "Prada Cup Semi-Final Day 1". America′s Cup. 29 January 2021. Archived from the original on 29 January 2021. Retrieved 29 January 2021.
  18. ^ Todd Niall (27 October 2020), Brazilian designer claims patent for AC75 canting foils, Stuff Ltd
  19. ^ NZ 740860