Naval architects designate sailboat rig types by number and location of masts. The six designations are sloop, cutter, cat, ketch, yawl, and schooner. Although in defining and describing these six rigs I may use terminology associated with the sail plan, the rig type has nothing to do with the number of sails, their arrangement or location. Such terms that have no bearing on the rig type include headsail names such as jib, genoa, yankee; furling systems such as in-mast or in-boom; and sail parts such as foot, clew, tack, leach, and roach. Rig questions are one of the primary areas of interest among newcomers to sailing and studying the benefits of each type is a good way to learn about sailing. I will deal with the rigs from most popular to least.
Sloop
The simplest and most popular rig today is the sloop. A sloop is defined as a yacht whose mast is somewhere between stations 3 and 4 in the 10 station model of a yacht. This definition places the mast with two thirds of the vessel aft and one third forward. The sloop is dominant on small and medium sized yachts and with the shift from large foretriangles (J-dimension in design parlance) to larger mains a solid majority on larger yachts as well. Simple sloop rigs with a single headsail point the highest because of the tighter maximum sheeting angle and therefore have the best windward performance of the rig types. They are the choice for one-design racing fleets and America’s cup challenges. The forestay can attached either at the masthead or some fraction below. These two types of sloops are described respectively as masthead or fractionally rigged. Fractionally rigged sloops where the forestay attaches below the top of the mast allow racers to easily control head and main sail shapes by tightening up the backstay and bending the mast.
Cutter
A cutter has one mast like the sloop, and people rightfully confuse the two. A cutter is defined as a yachts whose mast is aft of station 4. Ascertaining whether the mast is aft or forward of station 4 (what if it is at station 4?) is difficult unless you have the design specifications. And even a mast located forward of station 4 with a long bowsprit may be more reasonably referred to as a cutter. The true different is the size of the foretriangle. As such while it might annoy Bob Perry and Jeff_h, most people just give up and call sloops with jibstays cutters. This arrangement is best for reaching or when heavy weather dictates a reefed main. In moderate or light air sailing, forget the inner staysail; it will just backwind the jib and reduce your pointing height.
Ketch
The ketch rig is our first that has two masts. The main is usually stepped in location of a sloop rig, and some manufactures have used the same deck mold for both rig types. The mizzen, as the slightly shorter and further aft spar is called, makes the resulting sail plan incredibly flexible. A ketch rig comes into her own on reaching or downwind courses. In heavy weather owners love to sail under jib and jigger (jib and mizzen). Upwind the ketch suffers from backwinding of the mizzen by the main. You can add additional headsails to make a cutter-ketch.
Yawl
The yawl is similar to the ketch rig and has the same trade-offs with respect to upwind and downwind performance. She features two masts just like on a ketch with the mizzen having less air draft and being further aft. In contrast and much like with the sloop vs. cutter definition, the yawl mizzen’s has much smaller sail plan. During the CCA era, naval architects defined yawl as having the mast forward or aft of the rudderpost, but in today’s world of hull shapes (much like with the sloop/cutter) that definition does not work. The true different is the height of the mizzen in proportion to the main mast. The yawl arrangement is a lovely, classic look that is rarely if ever seen on modern production yachts.
Schooner
The schooner while totally unpractical has a romantic charm. Such a yacht features two masts of which the foremost is shorter than the mizzen (opposite of a ketch rig). This change has wide affects on performance and sail plan flexibility. The two masts provide a base to fly unusual canvas such as a mule (a triangular sail which spans between the two spars filling the space aft of the foremast’s mainsail). The helm is tricky to balance because apparent wind difference between the sails, and there is considerable backwinding upwind. Downwind you can put up quite a bit of canvas and build up speed.
Cat
The cat rig is a single spar design like the sloop and cutter, but the mast location is definately forward of station 3 and maybe even station. You see this rig on small racing dinghies, lasers and the like. It is the simplest of rigs with no headsails and sometimes without even a boom but has little versatility. Freedom and Nonesuch yachts are famous for this rig type. A cat ketch variation with a mizzen mast is an underused rig which provides the sailplan flexibility a single masted cat boat lacks. These are great fun to sail.
Conclusion
Sloop, cutter, ketch, yawl, schooner, and cat are the six rig types seen on yachts. The former three are widely more common than the latter three. Each one has unique strengths and weaknesses. The sloop is the best performing upwind while the cat is the simplest form. Getting to know the look and feel of these rig types will help you determine kind of sailing you enjoy most.