2014 saw the first annual Varsity Henley Swim. The Henley Classic is a 2.1km endurance event held at the Henley Royal Regatta course, very early on the Sunday morning before the Wednesday start of the Royal Regatta. The event is a celebration of mid-summer. 4 men and 4 women from each of Oxford and Cambridge make up two teams that battle it out over the course, aiming to have the lowest cumulative time and be crowned overall winner. In 2017, Cambridge took victories across the board for the time since the inaugural event.
In 2018, there will be annual the Varsity Match, an alumni match, and a mass participation event, each offering the opportunity for fierce rivalry between the universities.
More information about the event is available here: http://henleyswim.com/events/henley-classic/