The boats (or shells) are basically of two types and reflect the two forms of rowing – sweep rowing and sculling. In sweep rowing each rower handles a single oar (about 12.5 ft or 3.9 m long) in sculling a rower uses two oars, or sculls, (each about 9.5 ft or 3 m long). The word shell is often used in reference to the boats used because the hull is only about 1/8" to 1/4" thick to make it as light as possible. These shells are also rather long and racing shells are as narrow as possible while recreational ones can be rather wide. Most shells today are made of composite materials such as carbon fiber, fiberglass, or kevlar. A few manufacturers still build wooden boats.
Each rower has his back to the direction the shell is moving and power is generated using a blended sequence of the rower's legs, back and arms. The rower sits on a sliding seat with wheels on a track called the slide.
Each oar is held in a U-shaped swivel (oarlock) mounted on a metal pin at the end of a rigger. The rigger is an assembly of tubes that is tightly bolted to the body of the shell. The subtypes of rowing shells are classified according to the number of rowers in the shell.
Sweep Boats (each rower has one oar)
These shells can have a coxswain---a person who steers the shell (using a rudder) and urges the rowers on. I have included in parenthesis the symbol used for each subtype along with some dimensions and weights.
Sculling Boats (each rower has two oars)
Only in rare cases do these boats have a coxswain. Steering is generally accomplished by applying more power or pressure to the oar(s) on one side of the shell. The hands overlap (usually left over right in the US) during part of the rowing cycle, or are always left in front of right.