The Louis Vuitton America’s Cup World Series use foiling AC45 catamarans, also known as AC45f, a one-design wingsail catamaran with foils designed specifically for the for the event by the Oracle Racing engineering team.

The AC45 was conceived as a smaller version of the larger AC72 class rule which was sailed by competitors during the 2013 Louis Vuitton Cup and the 34th America's Cup.


  • Build: honeycomb core & carbon fibre sandwich
  • Length: 13.45m (44.1ft)
  • Beam: 6.90m (22.6ft)
  • Weight: 1,290–1,320kg (2,840–2,910 lb)
  • Maximum draught : 2.7m (8ft 10in)
  • Rig height: 21.5m (71ft) without extension, 25.5 m (84ft) with extension
  • Wing: 20m (66ft) 83.5m2 (899sq ft) wing element with three slotted flaps
  • Extension: 4m (13ft) high, 8.7m2 (94sq ft) area
  • Jib area: 48 m2 (520 sq ft), manufactured by a sail loft of team's choice
  • Gennaker area: 125 m2 (1,350 sq ft), manufactured by a sail loft of team's choice
  • Builders: Core Builders (NZ), Cookson Boats (NZ)
  • Crew: 5 + 1 guest


It is a state-of-the-art catamaran (twin hulls) with a solid aeroplane wing-like sail and sexy go faster hydrofoils to provide lift, speed and an unbelievable wow factor.

This lightweight rocket ship, which can reach speeds of up to 50 knots, is a smaller version of the AC72, which was used in the 2013 Louis Vuitton Cup and the 34th America’s Cup.

It was created as a relatively inexpensive boat to transport and sail so that teams could spend time on board to develop the skills needed to understand foil-style racing. It has also been invaluable in the development of the new AC48 which will be used for the 35th America’s Cup.

To make racing as fair as possible the AC45F is a strict one-design, which means each boat is designed to the same set of rules and built from the same yard. The components on the boats such as the wingsail, crossbeams (which hold the two hulls together), the spine, and the bowsprit (the pointy spike at the front that supports the forward sail) are also manufacture controlled.

The development of hydrofoils in the last two years has created a totally new style of sailing that has seen even the world’s best sailors – even Sir Ben Ainslie - having to learn new skills.

Gone are the days when it was possible to have the time to discuss tactics on the long run to the next mark. Now it is all about monitoring flap and foil angles, making decisions and completing manoeuvres in the blink of an eye and being fitter than ironman.

The AC45F is physically the hardest boat these sailors have ever sailed, said Land Rover BAR’s wing trimmer Paul Campbell-James.

“It’s a huge handful, but the rewards are big. Sailing at over 30 kts in a fleetrace is a truly awesome experience."

“My job is to trim the wing, which is a similar role to a mainsheet trimmer. Like every role on the boat, it is physically and mentally demanding."

"The loads are bigger than on a more conventional boat so being athletic and AC45- sailing fit is crucial." 

“Ben at the helm is in charge of the lift of the boat with a hydraulic and battery-driven rake system controlled from a switch on a panel just in front of him. There’s never a dull moment, that’s for sure.”


1. Helmsman

The helm is the mastercommander, deciding how the boat goes round the race course. With the tactician, he or she communicates a plan to the rest of the team. In a foiling boat he also controls the boat on the hydro foils. Lose concentration and the boat slows down and comes off the foil or worse, crashes if it flies too high. Split second decisions are essential. Not a job for ditherers.

2. Wing Trimmer

Controls the enormous wing sail which is the driving force behind the boat. Also helps in the manoeuvres to get the daggerboards up and down. In some teams the wing trimmer is also tactician, constantly watching the wind and what the other boats are doing and feeding this back to the helm.

3. Grinder

The main power source for winding winches and pulling stuff hard. These guys work at full capacity the whole race. When they are not winding winches they are lifting boards up, winding the code zero (front sail) in or hiking (leaning out) as hard as they can.

4. Trimmer

Controls the front two sails, the smaller Jib and the code zero which is used downwind in the lighter winds. This is a busy role working with the wing trimmer and helm to keep the boat quick at all times and helping to move the boards up and down in the manoeuvres.

5. Bowman

The utility man normally built like a brick outhouse. The first to cross the boat for a change of course, sets everything up on the opposite side ready for each manouvre. Bowmen have to be quick and nimble on their feet, a job requiring very meticulous routine to ensure there are no hiccups.