Italy's AC75 boat took a dramatic, high-speed nosedive during the latest race against Britain in their America's Cup challengers clash on Tuesday, damaging their carbon fibre decking and handing their opponents a win and 4-3 lead.

Ineos Britannia’s chances of making the 37th America’s Cup received a huge boost on Wednesday, although not in the way they would have wanted after Italian rivals Luna Rossa sustained damage to their boat in race seven.

Italy's Luna Rossa Prada Pirelli surprised its rivals at the last America's Cup by showing up with two helmsmen to steer its foiling yachts.

Britain and Italy were level-pegging in the first-to-seven America's Cup challenger final on Thursday, with one win apiece.

British co-helm Dylan Fletcher said he feared “someone might have been killed” had Ineos Britannia not taken evasive action during Sunday’s controversial loss to Luna Rossa, which allowed the Italians to draw level at 2-2 in the Louis Vuitton Cup final.

Gone are the days of sailors running rigging and pulling lines. Now, the elite athletes, called "cyclors," are cooped up in the hull, cycling furiously to create the hydraulic power used to control the boat's sails and hydrofoils.

Italy's AC75 boat took a dramatic, high-speed nosedive during the latest race against Britain in their America's Cup challengers clash on Tuesday, damaging their carbon fibre decking and handing their opponents a win and 4-3 lead.