The 29-year-old has long sailed with Nic Asher in the 470 class, winning two World Championship titles in 2006 and 2008, however an appearance at the Olympic Games eluded them.
They missed out on a spot at Beijing 2008 to Athens 2004 silver medallists Nick Rogers and Joe Glanfield, the pair going on to finish second again, and then Luke Patience and Stuart Bithell for London 2012.
Patience and Bithell continue Britain's silver-medal winning trend at London 2012 but have since split while Glanfield, after retiring following Beijing 2008, is back but not with Rogers.
Glanfield has joined forces with Patience after he and Bithell chose to take different paths to the Rio 2016 Olympics while Rogers called time on his partnership with Chris Grube with Willis and Asher following suit.
Willis and Rogers have now partnered up with each other in the 470, that arriving at the beginning of 2013, with their first competitive appearance coming at this week's World Cup in Hyeres.
And, while admitting it was never going to be easy splitting from long-term partner Asher, who has switched to the 49er, Willis admits the change can spur him on to finally appearing at the Olympics.
"To a certain extent it is unfinished business," said Willis. "But for me it is a really exciting opportunity to develop myself as a sailor. It is always hard when you've known someone for that period of time.
"We've pretty much grown up together since the age of ten but it got to the stage where we both kind of knew what we wanted out of our sailing careers. Nic fancied a change of class, and was probably a little bit big to helm a 470.
"In the first few months it's been a huge learning curve being part of a new team and having the motivation to start a new campaign up.
"It's been a lot of fun as well. It's new, fresh, exciting and looking forward we both have skills that complement each other, so it's exciting stuff for us.
"We're excited to get back racing again. For us [this week] is more about cementing what we've been doing in training.
"We have our own goals for the event and we'll see what happens, but we're very excited to get started.
"Nick has got great skills when it's windy and is obviously a very, very experienced 470 sailor with two silver medals. Between us we have quite a lot of experience in the class."
- Sports & Recreation
- Joe Glanfield
- Stuart Bithell
- Luke Patience
- Nic Asher