Although he did not row for Oxford, his brother, Richard Somers-Smith took part in the Boat Race in 1904 and 1905. The Magdalen College Coxless four that John rowed with won the Wyfold Challenge Cup and the Visitors' Challenge Cup in 1907, with another double win in the Stewards' and the Visitors' at the Henley Royal Regatta in 1908, and was selected to represent Great Britain in rowing at the 1908 Summer Olympics, Somers-Smith was stroke of the four along with Collier Cudmore, James Angus Gillan and Duncan Mackinnon. This crew won the gold medal for Great Britain, defeating another GB Leander crew, and crews from Canada and the Netherlands.
Although he did not participate in rowing at Oxford, his brother Richard Somers-Smith competed in the Boat Race in 1904 and 1905. The Magdalen College Coxless four that John coxed with won the Wyfold Challenge Cup and the Visitors' Challenge Cup in 1907, with another double win in the Stewards' and the Visitors' at the Henley Royal Regatta in 1908, and was chosen to represent Great Britain in rowing at the 1908 Summer Olympics, Somers-Smith was stroke of the four along with Collier Cudmore, James Angus Gillan and Duncan Mackinnon. This crew won the gold medal for Great Britain, defeating another GB Leander crew, and crews from Canada and the Netherlands.