The 2005 UIM F1 World Championship was the 22nd season of Formula 1 Powerboat racing. The calendar consisted of six events, beginning in Portimão, Portugal on 22 May 2005, and ending in Sharjah, UAE on 16 December 2005. Guido Cappellini, driving for the Tamoil F1 Team, clinched his ninth world title, re-taking the championship from defending champion Scott Gillman.[1]