operating a pair of oars, one on each side of the boat. When each person uses a single oar on one side of the boat, that action is termed "pulling". In fresh water terminology, "rowing" is the use of one oar per person, whilst "pulling" denotes each person using two oars. Traditional boats propelled by oar are fitted with thwarts - seats that go from one side of the hull to the other, as well as forming part of the hull structure. A boat that is "double banked" has two crew members sitting on each thwart, each pulling an oar on their side of the boat. In a "single banked" boat, there is one person on each thwart pulling one oar. Though there is usually an even number of oars used in single banked boats (alternating port and starboard along the length of the boat) a common exception is the arrangement in many whaleboats, where five oars were often used, three on one side and two on the other. In traditional rowing craft, the pivot point of the oars is generally located on the boat's gunwale. The actual fitting that holds the oar may be as simple as one or two pegs (or thole pins) or a metal oarlock (also called rowlock - "rollock"). In performance rowing craft, the rowlock is usually extended outboard on an outrigger or rigger to allow the use of a longer oar for increased leverage and power. Sculling involves a seated rower who pulls on two oars or sculls, attached to the boat, thereby moving the boat in the direction opposite that which the rower faces. In some multiple-seat boats seated rowers each pull on a single "sweep" oar, usually with both hands. Boats in which the rowers are coordinated by a coxswain are referred to as a "coxed" pair/four/eight. Sliding seats are often used to enable the rower to use the leg muscles, substantially increasing the power available. An alternative to the sliding seat, called a sliding rigger, uses a stationary seat with the rower's legs and feet moving the rigger and oarlocks. On a moscone, a catamaran used in Italy, the rower sits or may stand, taking advantage of body weight to increase leverage while sculling. Forward-facing systems Push rowing, also called back-watering if used in a boat not designed for forward motion, uses regular oars with a pushing motion to achieve forward-facing