Somerville successfully completed the English Channel on 23 September 2011 in 12 hours 30 minutes and who attempted a North Channel crossing in July 2012. His English Channel crossing was the 12th fastest time by an Irish swimmer, 7th fastest Irishman, and fastest over age of 40. He also completed the North Channel during his second attempt on 16 June 2013 and completed the channel swim in 12 hours 21 minutes.
The member of the Eastern Bay Swim Team in Dublin, he swims year round at High Rock in Malahide (Dublin) and recorded the first Inis Meáin to Rosaveel swim along the Galway Coast and also pioneered the Dublin Bay 2- way swim in 2012.
Global Open Water Swimming Conference
Somerville will speak at the 2013 Global Open Water Swimming Conference, a conference hosted and organised by Oswald Schmidt, Paschal Horgan, Captain Tom McCarthy, Ciaran O'Connor, Finbarr Hedderman, and Ned Denison in Cork, Ireland. The other presenters include Professor Tom Doyle, Trevor Woods, Dr. Angel Yanagihara, Dr. Lunt & Dr. Adams, Kevin Murphy, Niek Kloots, Sally Minty-Gravett, and Wayne Soutter.