Ineos Britannia skipper Ben Ainslie believes the British team face the "ultimate challenge" in trying to pry a first America's Cup away from double defending champions Emirates Team New Zealand in Barcelona.

New Zealand have been analysing patterns in Ben Ainslie's racing, honing their technique and making subtle final adjustments to the sails and foils of their AC75 boat as the America's Cup holders prepare for the British challenge.

Here we go: it’s the oldest trophy in sport, it’s a potential 13 races on the seas of Barcelona and it’s a British team masterminded by Sir Ben Ainslie and Sir Jim Ratcliffe going up against the ‘All Blacks of the Sea’,

Britain and holders New Zealand go head-to-head on Saturday in the opening two races of a first-to-seven series to determine the winner of the America's Cup, with Ben Ainslie's British team in the final for the first time in 60 years.