a balanced, coxed boat. The physical movement of sculling is split into two main parts: the drive and the recovery. These two parts are separated by what is called the "catch" and the "finish". The drive is the section of the rowing stroke where the face of the oars, also known as blades, are firmly placed in the water and the rower is propelling the boat forwards by pulling against the anchor the oars provide. The recovery is the section where the rower's blades are not in the water, but instead gliding above it as the rower prepares for the next stroke. The catch is the moment the blades are dropped into the water at the end of the recovery and the start of the drive, while the finish is when the blades are slipping out after the drive is done and the recovery is beginning. In order to improve balance on the recovery, the blades are feathered, or held parallel to the surface of the water, at the finish, and squared (perpendicular to the water surface) at the catch. Competitive crew requires an efficient stroke with all rowers matching the cadence and movements of the stroke seat, the rower closest to the shell's stern. The shell may have a coxswain, or "cox", to steer the boat, encourage the crew, and monitor the rate, though coxswains are highly uncommon in competitive sculling shells and the rower in bow seat usually takes on these responsibilities instead. The bow-most rower may have equipment that attaches the skeg of the shell to one of the bow's shoes to aid with the steering; without such equipment, a sculling boat is directed by uneven pressure applied to the opposing blades. A key technical difference between sculling and sweeping in crew is that the sculling oar handles overlap twice during the stroke cycle (sweep oar handles never overlap during normal rowing because each sweeper usually holds only one oar). The overlap occurs at the midpoint of the drive and again during the recovery; because of this, scullers must hold one hand (conventionally the left hand) higher than the other at the point of overlap. To prevent this from impacting the balance of the boat, one oarlock (conventionally the starboard one, to the rower's lefthand side) is rigged higher than the other prior to rowing. This prevents the oar handles and the sculler's thumbs from colliding with