The 35-year-old became the most successful Olympic sailor of all time this summer, collecting a fourth gold that, coupled with the silver picked up in Atlanta, saw him usurp Denmark's legendary Paul Elvstrom.
Few had expected Ainslie to add to that haul in Rio de Janeiro due to America's Cup commitments and the toll dinghy sailing was having on his body.
It was a move that was confirmed on Tuesday morning and one that leaves him excited for the future.
"It is the close of one chapter and start of another," said Ainslie.
"I am obviously not retiring from sailing in general, it is just the Olympic side of the sport.
"In many ways, it is actually quite exciting to be able to focus 100 per cent on this new project with the America's Cup.
"That is really the main reasoning behind it and also, in some ways, due to the class selection for 2016. It didn't necessarily help with the injuries I've had over the last 12 months.
"Really, after some careful consideration, it was the right decision to take and it is a good one."
It has been quite a year for Ainslie, who not only took Olympic gold but a record sixth Finn Gold Cup on his home waters in Falmouth.
The Lymington-based sailor was named ISAF Rolex World Sailor of the Year for a record-breaking fourth time and claimed the British Olympic Association's Athlete of the Year Trophy for Sailing for a third time.
He was also yesterday named amongst the 12 contenders for BBC Sports Personality of the Year - an accolade never before won by a sailor.
"It is a special honour, especially with such an amazing of year of sport in Britain," Ainslie said of the news.
"It is a real honour to be part of that group and a part of that amazing year. It will be a fantastic evening.
"It is a good old saying that you should quit while you're ahead.
"Certainly I have had a fantastic year. I have been very fortunate to have a great Olympic career and this is the right time to bow out with a really exciting new challenge ahead."
That challenge will see him look focus on the America's Cup and the team he launched in January.
Ben Ainslie Racing (BAR) are currently competing in the 2012/13 America's Cup World Series and were formed with a long-term vision of challenging for the 35th America's Cup.
Ainslie will be Oracle Team USA helmsman in the 34th edition and wants to add America's Cup glory to his Olympic successes.
"I am enjoying my sailing more now than perhaps ever," he said.
"I think would have found the motivation to continue for 2016 if I had chosen to do that, but really the America's Cup is the big goal to try and achieve as part of a winning team.
"That is the focus now and in the past I have been involved with the America's Cup and never really been focused 100 percent due to Olympic commitments.
"Maybe there was a realisation there of if I am going to be successful and be part of a winning team, I need to give 100 percent focus.
"Things are going really well with J.P. Morgan BAR.
"It has gone really well with America's Cup World Series regattas and now we're trying to put the pieces together to build up to a full-blown America's Cup team after next summer.
"That is the 35th America's Cup and in the meantime I am involved in Oracle Team USA, who are the defending team, and we're busy developing the boats and the boat which will ultimately race in that America's Cup next September.
"It is a busy time, there is plenty going on and the most important thing is that we can build this team up, J.P. Morgan BAR, to have what it takes to go out and be successful and bring the America's Cup back to British waters."