Sailing: Sir Ben Ainslie's INEOS TEAM UK tests America's Cup yacht prototype

INEOS tests its new AC75 America's Cup prototype. Photo / Facebook

If we know anything about the 2021 America's Cup yachts, it's that they will float.

Since Team New Zealand's innovative AC75 fully-foiling monohull design was revealed late last year, sailing enthusiasts have been curious to see what the radical design could look like on the water.

And now a video posted to Facebook by London Corinthian Sailing Club has given an exclusive sneak peek to what appears to be INEOS TEAM UK's first prototype.

The high performance fully foiling monohulls are expected to be potentially faster than the catamarans sailed last year in Bermuda with TNZ's goal of designing a class that would be both challenging and demanding to sail.

The smaller QUANT 23 seen in the video appears quite stable in flight mode although it is not known whether the foiling is under manual or full computer control.

Sail-World reported that the prototype was sailing downwind at speeds of 30kts in 12kts of wind, and upwind at 20kts while performing foiling tacks and gybes with relative ease.

The British team are the first to launch a prototype while other teams are believed to have similar projects underway with the first permitted launch date for the first AC75 just over eight months away.

INEOS TEAM UK, led by Sir Ben Ainslie, will challenge New Zealand in the next America's Cup in a bid to claim the prestigious Auld Mug after 21 British challenges.

Aided by a whopping $216 million war chest, Ainslie believes the 36th regatta will be Britain's best opportunity yet.

In the few months since INEOS put their full support behind the British challenge, the team has been quietly recruiting some of the best America's Cup sailors and designers, including former Team New Zealand designer Nick Holroyd.

The 2021 campaign will be the second for Ainslie's team, who were expected to again be among the contenders after making the challenger semifinals on the Great Sound.

Meanwhile, Team New Zealand announced the good news this morning that Peter Burling and Blair Tuke will take part in TNZ's defence.

The Kiwi sailing duo also confirmed their intention to try to win another gold medal at the 2020 Tokyo Olympic Games.