On Thursday, the four-time Olympic sailing gold medalist announced a shock £110 million ($153m) shakeup of his former Land Rover BAR America's Cup team.
The 41-year-old unveiled the record title sponsorship from INEOS, a petrochemicals company owned by Britain's second-richest man James Ratcliffe.
The new look INEOS TEAM GB ends a four-year collaboration with British car brand Jaguar Land Rover, as Ainslie accelerates his second attempt to win the America's Cup for Britain.
In a joint statement with INEOS, Ainslie called the deal "an amazing boost for British sport."
Although the America's Cup, sailing's most prestigious event, was first held in Britain in 1851, no team from the British Isles has ever lifted the "Auld Mug."
Last year, Ainslie's rookie Land Rover BAR team were knocked out by eventual winners New Zealand in the semi-finals of the challenger series in Bermuda.
The decision by Ainslie, who was part of Oracle Team USA's Cup-winning team in 2013, did not go down well with Land Rover.
"We are extremely disappointed having worked tirelessly to support Ben and the entire team," Land Rover said in an emailed statement on Thursday, adding that they were told INEOS had bought the team and that its contract was terminated on April 20.
"It is a great blow to us all that our partnership will not continue."
Speaking by phone to CNN from London, Ainslie said the increased cost of the 2021 America's Cup campaign had played an important part in his decision.
As defender of the longest continuous international competition in sport, Team New Zealand has decided the next America's Cup will be staged in a new class of boat. Instead of the twin-hulled foiling catamarans used in Bermuda, the 2021 Cup finals in Auckland will be held in 75-feet foiling monohull yachts.
"There is a completely new concept of boat, two 75-feet foiling monohulls, and the costs have gone up significantly and it requires a different approach," Ainslie said, after thanking Land Rover and his other backers for their support in his previous Cup bid.
"It was approximately a 30 percent increase in budget and we looked very long and hard at how we could fund the team.
"It became clear that the proposal from INEOS -- although it's a completely new team and structure -- also gives us that commitment level of funding to be able to build the right strategy, a winning strategy, to take on this technical and sailing challenge."
Although Ainslie acknowledged his previous investors and partners "are all disappointed that they're unable to remain involved with the team," he said "this was ultimately the team's decision and my decision to move forward under this new structure because of the commitment to the budget that we now have."
Ainslie pointed out that in the 167-year history of the America's Cup, only one rookie team had been successful -- Swiss syndicate Alinghi in 2003.
"We achieved a huge amount in the last campaign, and everyone was very proud of that," he said of his 130-man strong Land Rover BAR team, which consisted of engineers, aerodynamicists, designers and sailors who implemented high-end technology and concepts from the motor industry.
"To put a new team together in such a technical challenge is traditionally very, very difficult."
Still, Ainslie's team had gone into the Cup finals in Bermuda as one of the favorites after winning the 2015-16 World Series ahead of far more established teams, including defending champion Oracle Team USA and Emirates Team New Zealand.
But New Zealand sprung a massive surprise when they showed up with radical cycle-style grinders instead of the traditional arm-powered winches to drive the hydraulic systems. Their gamble -- that increased leg power would outweigh disadvantages such as inefficiencies in getting on and off the bikes -- paid off as they won the Cup easily in the final against the US.
'Fight chance of success'
Since Bermuda, Ainslie has hired some of the most experienced people in sailing to take his quest on.
These include four-time Cup winner Grant Simmer as chief executive, British Olympic sailing champion Giles Scott as tactician and Nick Holroyd, one of the men responsible for Emirates New Zealand's Cup winning strategy, as chief designer.
"A huge amount was achieved, but we ultimately weren't quick enough at the end of the day," Ainslie said. "And that's been our key focus in the period since the last America's Cup, to get the right designers in place and the right team and structure in place to have a winning team."
Ratcliffe, founder and chairman of INEOS, the UK's biggest privately-owned company and one of the country's top fracking firms, is hopeful his investment will bring back the Cup to Britain for the first time.
"With the team we have assembled, we believe we can get a fully competitive boat to the start line," said the 65-year-old Ratcliffe, who has a $16.4 billion fortune according to Forbes.
"After that it's all down to the fine art of sailing. Ben is arguably the best sailor that Britain has ever produced so we should have a fighting chance of success."