Starting from Aldermaston Bridge, Thameside 1 is a 12-mile, 13 portage time trial down the Kennet & Avon Canal, through Reading town centre and out onto the River Thames.
A left turn where the mouth of the Kennet meets the Thames takes competitors upstream and over Caversham Lock, finishing upstream of Caversham Bridge at Reading Canoe Club on the right hand bank.
The finish was historically at the Longridge Activity Centre, Quarry Wood Road, Marlow, until 2022.
This race encompasses the Henley Straight - a 2-mile stretch over river running through Henley-on-Thames, Oxfordshire, which is notorious for its strong head and side winds.
However, the two series on their own are often considered to be good challenges in themselves, and are competed particularly strongly in the Junior K2 section by schools.