He got his first cap for Fiji on 26 May 2007 in a 30–15 win over Japan. Dewes was a member of the Fiji squad that entered the 2007 Rugby World Cup finals, playing in four matches and scoring the winning try in the 38–34 win over Wales putting Fiji through to their first quarter final in 20 years. Fiji lost that quarter final to eventual winners South Africa despite drawing 20-all for a period in the 2nd half. He had 7 caps by the end of the competition. His mother is Rotuman from Noa'tau, Rotuma. Before his selection into the 2007 squad he had only played third division rugby in the NPC in New Zealand. He played in Auckland's age grades through to U-23s, and Thames Valley in the NPC. He currently plays for Counties Manukau Steelers in New Zealand.