Get Involved Charity Events Swim Oxford - 4KM An open water downstream swim in the river Thames from Eynsham Lock to Kings Lock. The river Thames meanders through picturesque landscapes set in these Oxford Universities organic pastures. This is a beautiful stretch of river for an open water swimming event. We recommend that swimmers are experienced in open water swimming and be able to complete the 4K distance within 2 hours. You should be comfortable swimming this distance in water temperatures of 12c -16C. For more information or to sign up click the 'Book Now' button below Booking for this event has now closed. Book Manage Cookie Preferences