In watercraft, a racing shell (also referred to as a fine boat (UK) or simply a shell) is an extremely narrow, and often comparatively long, rowing boat specifically designed for racing or exercise. It is equipped with long oars, outriggers to hold the oarlocks away from the boat, and sliding seats. The boat's long length and semicircular cross-section reduce drag to a minimum. This makes the boat both fast and unstable. It must be balanced by the rowers to avoid tipping. Being able to balance – or "set" – the boat while putting maximum effort into the oars is therefore an essential skill of sport rowing.