A coxless four is a
rowing boat used in the
sport of competitive rowing. It is designed for four persons who propel the boat with
sweep oars, without a
coxswain.
The crew consists of four rowers, each having one
oar. There are two rowers on the
stroke side (rower's right hand side) and two on the
bow side (rower's lefthand side). There is no
coxswain, but the
rudder is controlled by one of the crew, normally with the rudder cable attached to the toe of one of their shoes which can pivot about the ball of the foot, moving the cable left or right. The steersman may row at bow, who has the best vision when looking over their shoulder, or on straighter courses stroke may steer, since they can point the stern of the boat at some landmark at the start of the course. The equivalent boat when it is steered by a coxswain is called a "
coxed four".
Racing boats (often called "shells") are long, narrow, and broadly semi-circular in cross-section with gradual tapers, causing little drag. Originally made from
wood, shells are now typically made from a
composite material, usually
carbon fiber reinforced polymer
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...
, for strength and weight advantages. Fours have a fin near the stern, 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. A sweep-oared boat has to be stiffer to handle the unmatched forces, and so requires more bracing, thus slightly heavier, inside, than a boat optimally designed (instead) for sculling.
"Coxless four" is one of the classes recognized by the