 Dumais placed 6th in the 2004 Summer Games Men's 3m Synchronized Spring Board with his brother, Justin Dumais.He also placed 6th at the Beijing 2008 Summer Olympics in the Men's 3m Individuals, making that his third 6th-place Olympic finish in a row.With diving teammate Kristian Ipsen, he took the silver medal in the Men's 3m Synchronized Springboard at the 2009 World Aquatics Championships in Rome, Italy, and the bronze medal in the Men's 3m Synchronized Springboard finals at the London 2012 Summer Olympics.