An eight is a rowing boat used in the sport of competitive rowing. It is designed for eight rowers, who propel the boat with sweep oars, and is steered by a coxswain, or cox. Each of the eight rowers has one oar. There are four rowers on the stroke side (rower's right hand side) and four on the bow side (rower's lefthand side). The cox steers the boat using a rudder and is normally seated at the stern of the boat. Because of the speed of the boat, it is generally considered unsafe to row coxless or to have a bowloader cox. Racing boats (often called "shells") are long, narrow, and broadly semi-circular in cross-section in order to reduce drag to a minimum. Originally made from wood, shells are now almost always made from a composite material (usually carbon-fibre reinforced plastic) for strength and weight advantages. Eights have a fin towards the rear, to help prevent roll and yaw and to help the rudder. The riggers are staggered alternately along the boat so that the forces apply asymmetrically to each side of the boat. If the boat is sculled by rowers each with two oars the combination is referred to as a octuple scull. In a scull boat, the riggers apply forces symmetrically. A sweep oared boat has to be stiffer to handle the unmatched forces, and so requires more bracing, which means it has to be heavier and slower than an equivalent sculling boat. However octuple sculls are not used in main competitions. "Eight" is one of the classes recognized by the International Rowing Federation and one of the events in the Olympics. Sweep or sweep-oar rowing is a type of rowing when a rower has one oar, usually held with both hands. As each rower has only one oar, the rowers have to be p
ired so that there is an oar on each side of the boat. This is in contrast to sculling when a rower has two oars, one in each hand. In the UK the term is less used as the term rowing generally refers to sweep oar. The term pulling was also used historically. Sweep or single oar rowing has a long history and was the means of propulsion for Greek triremes and Viking longboats. These boats were wide enough for the pairs of rowers to sit alongside each other. Boats can go faster, the narrower they are, because a smaller cross-sectional area reduces drag and wave drag and gives a sharper angle to the bow. The hulls can be kept narrower by attaching riggers to the gunwales, so that the oarlocks can be placed farther out to carry longer oars. A narrower hull means the rowers can not sit side by side and so they sit one behind another. The riggers are staggered alternately along the boat so that the forces apply asymmetrically to each side of the boat. This means a sweep oared racing shell has to be stiffer in order to handle the unmatched forces, and so requires more bracing, which means it has to be heavier and slower than an equivalent sculling boat. Sweep rowing has to be done with crews in multiples of two - i.e. pairs, fours and eights (sixes and boats longer than eight are not used in competitive racing today). Each rower in a sweep boat is referred to as being on stroke side (port) or bow side (starboard), depending on which side of the boat the rower's oar extends. In a sculling boat the riggers apply forces symmetrically. While sculling boats are also in multiples of two, it is possible to have a Single scull or Triple scull. The primary sweep oar racing boats are as follows.