Boat types

Boats are divided into two main categories, namely sculls and rowing boats. With sculls each oarsman has two sculling oars whereas with rowing boats each oarsman has one sweep oar.

Boats also are numbered to show how many oarsmen are in the boat. Some boats have a coxswain and others do not.

The following diagrams show the layout of various types of boat (graphics borrowed from another rowing website):

Sculls

Type of boat	Notation	Diagram - Note that each oarsman has an oar on the far side as well.
Single	1x	This loner has to do it all himself/herself.
Double	2x	Two rowing in tandem.
Coxed double	2x+	The cox helps with steering and, mostly nowadays, coaching.
Quad	4x	The coxless quad is the fastest competitive boat - usually even faster than an eight.
Coxed quad	4x+	Coxed quads are common at schools.
Octuple (coxed)	8x+	Normally reserved for young trainee crews (under 14 age-group).

Rowing boats

Type of boat	Notation	Diagram - Note that each oarsman only has one oar
Pair	2-	Arguably the pinnacle of racing, requiring the most balance.
Coxed pair	2+	Cox added in this case, usually for coaching purposes.
Four	4-	This is a highly competitive class, fast and aggressive (but not requiring as many as an eight).
Coxed four	4+	As above but with a cox. Used a lot with school rowers and less experienced rowers, or on tighter courses.
Eight (coxed)	8+	The "full sized" boat that everyone knows from the Oxford-Cambridge boat race...