The World of Robert Jordan's The Wheel of Time wrote:The Atha'an Miere ships fall into four general classes. From smallest to largest they are the darter, soarer, skimmer, and raker. Anything smaller than a darter is considered a boat, not a ship. The fastest class of ship is the raker. Lean, long, and incredibly swift over the water, rakers always carry three masts and are square-rigged. The skimmer is also three-masted and is as long as a raker, but it is broader in the beam and of a greater displacement, which makes it slower than a raker, though usually much faster than any mainland ship of comparable displacement. The soarer, a two-masted vessel, while smaller than a skimmer, is faster and usually quite agile. The smallest of the Sea Folk vessels, the darter, can have one or two masts.
The ships vary in their rigging. "High-rigged" means that the major sails on every mast are square sails. "Half-rigged" means that at least one, but not all, masts carry no major square sails, but rather gaff sails. "Low-rigged" means that all masts carry gaff sails as the major, or only, sails. Thus "a half-rigged skimmer" is a skimmer-class vessel in which one or more, but not all, of the masts have square sails for the majors. A raker is always high-rigged, and it goes without saying.
These ships, far superior to any other oceangoing vessels in both speed and nmanageability, are the key to the Atah'an Miere's unquestioned dominance of the sea trade.
Note that any relative size information given here is NOT necessarily true IC. Find that out for yourselves! This is just a description that might be true.
Also, Atha'an Miere ships are referred to as "he". Not that that should make any difference in game, but then neither should our convention of calling ships "she".