Of all the thousands of pieces of equipment that Formula 1 hauls around the world, few are used less often than the full wet tire.

Sunday's Belgian Formula One Grand Prix was delayed by rain and poor visibility at the Spa-Francorchamps circuit after a formation lap behind the safety car.

SPA-FRANCORCHAMPS, Belgium - Heavy rain has delayed the start of the Belgian Grand Prix, where a topsy-turvy race appears to be in store. Rain started just as the cars made their way to the grid and intensified in the 30 minutes of build-up on the grid.