Put a Smaller Sail Aft
So far we have divided the working cloth around one mainmast. Now add a second support farther aft, carrying a smaller sail with its own controls. The crew gains another piece of cloth it can set, trim or lower independently, and another place along the hull at which wind can exert force.
Give the after sail its own support
The smaller mast aft of the mainmast is the mizzenmast. In the arrangement we are building, it supports a smaller mizzen sail. The mast has its own step and support: it must pass the sail’s loads into the hull whether it uses external stays or stands through its own bending strength. Lowering the cloth leaves that structural member in place.
The shortened word mizzen can mean either object. A mizzen with shrouds is a mast; a mizzen being reefed is a sail. In his 1889 account, E. F. Knight uses the word for the mast that a curved tiller must clear and also for the sail the crew can stow. Saying mizzenmast or mizzen sail makes the intended object explicit. Knight, Sailing, page 53.
Give this sail a boom. Its forward joint lets the spar swing at the mizzenmast; the sail’s clew is held towards the after end, with the outhaul controlling its position along the boom. This is the mizzen boom. Its own sheet restrains the boom’s sideways movement and carries load to the hull. The mainsail’s sheet still controls the other boom, farther forward. The crew can therefore change the two sails’ angles separately.
The sheet needs a useful pulling direction. When the mizzenmast stands very near the stern, the boom may reach beyond the deck. A stern bumpkin can project the lower sheet lead aft, just as a projecting support elsewhere moves a rope’s attachment into useful space. In the small-yacht arrangements described by E. F. Knight in 1889, that after-sail sheet leads through the bumpkin’s end. With the mizzenmast farther forward from the stern, Knight instead describes a sheet working through an aft deck block. The mast position changes the available sheet geometry as well as the sail’s position. Knight, Sailing, pages 52–55.
A mizzen can use a lug, gaff or triangular sail. The support form tells us how the cloth is held; mizzen identifies its place and role in this rig. Moving the principal forestay between a masthead and fractional attachment remains another independent choice. The one-mast masthead sloop and fractional sloop taught those heights; adding an aftermast gives the whole rig a further property without changing what either height means.
Select the cloth and change the force
Consider a boat carrying a headsail, mainsail and mizzen sail. With all three drawing, the total sail force includes the contribution of each. The mizzen can provide forward drive as well as sideways force. Its position aft also gives that sideways force a turning effect about the boat.
Lower the main while leaving the headsail and mizzen set. Two separated sails remain available, one forward and one aft. Their sheets let the crew alter their relative contributions while the main is being dealt with. Whether this pair provides enough drive for the intended course depends on the actual boat, sails and conditions. A little after sail cannot automatically replace a much larger main.
Alternatively, lower the mizzen and retain the headsail and a reefed main. The boat now has less after-sail force, and the remaining sail area is distributed differently. Reefing the main reduces its working area by securing a lower portion of cloth out of use; we will follow the arrangements for doing that later. Here the important change is which independently controlled areas remain exposed.
These are three distinct states of one rig: all three sails, headsail with mizzen, and headsail with reduced main. Their usefulness comes from selectable area and force position, rather than a promise that one combination works in every wind. The smaller operations also require more separate controls and attachments than one sail would.
The centre of effort represents the combined sail force for the particular working state. It moves when the sails’ contributions change. With the other forces initially comparable, adding sideways force well aft tends to push the stern leeward and turn the bow towards the wind. Easing or lowering that sail reduces its contribution. The hull, underwater surfaces, heel and rudder continue to matter, so drawing a geometrical centre between two masts cannot predict the complete steering balance. The crew is adjusting a working system, not simply placing an area marker on a plan.
This explains two useful jobs of the after sail. It supplies an independently selectable share of the drive, and it gives the crew a separately adjustable contribution to turning balance. Even a small mizzen can matter through its position. Later we will use the same force model when slowing a boat and, once anchoring is understood, when examining an after sail used to steady a boat at anchor.
Use the space ahead of the mizzen
The second mast also creates room for a light sail forward of it, commonly in the space between mainmast and mizzenmast. This is a mizzen staysail. Its exact attachments need checking: the traditional name includes examples set flying, with no continuous stay supporting the luff.
On John Hartmann’s WAXWING, a halyard passes through a block lashed at the mizzenhead and is secured at the mast step. A tack line reaches a forward windward cockpit cleat. The clew sheet passes through a low-friction thimble held at the after leeward gunwale, then reaches a cleat near the helm. These three routes support and control the flying sail. Hartmann describes it as an addition for reaching in light wind. His 2017 account.
The hoist loads the mizzenmast, while tack and sheet loads reach separated hull attachments. More cloth can now use the space between the masts, but it needs clearance from the main and its gear. Its forward tack also needs a suitable position as the boat changes tack. The extra sail adds a handling choice rather than becoming a permanent part of the mizzen sail behind the mast.
Name the two arrangements
We can now distinguish ketch and yawl using a declared convention. In World Sailing’s current equipment rules, both have a taller mainmast forward and a smaller mizzenmast aft. A ketch places the mizzenmast forward of the rudder stock. A yawl places it aft of the rudder stock. Equipment Rules of Sailing, F.1.2.
The stock is the member that turns with the rudder, already encountered beneath its tiller. Locate that physical reference along the hull, then locate the mizzenmast. A steering wheel can stand some distance from the rudder and transmit movement to it; its position does not establish this boundary. Older writers often say rudder post, so their intended rudder reference and naming practice need reading in context.
The yawl-versus-ketch comparison concerns scale and working space as well as the named boundary. Moving the aftermast forward from the stern can provide more room for its boom and a more substantial mizzen sail. Placing it far aft commonly accompanies a smaller sail and a longer turning arm. Neither name specifies an exact area ratio. A useful account should tell us how much cloth each mast carries and what remains when the main is lowered.
This is a present convention for understanding a described arrangement. Knight’s 1889 account called some boats yawls even when their mizzenmast stood just before the rudder head, with a curved tiller to clear it. Thomas Fleming Day’s 1901 account used the forward-or-aft rudder-post distinction more like the current rule. The difference is worth retaining when reading old yacht descriptions; moving the vocabulary through time without its convention would misidentify the boat. Knight, pages 53–54; Day, On Yachts and Yacht Handling, pages 97–98.
Combine two masts with the cat arrangement
Retain a principal sail set from a forward mainmast, omit the ordinary headsails ahead of it, and add the smaller mizzen in the ketch position. This is a cat-ketch. Use the yawl’s far-aft mizzen position with that cat-style principal sail and the result is a cat-yawl. Each compound combines the forward sail allocation with the aftermast arrangement. It does not prescribe the traditional Cape Cod catboat’s hull proportions.
B&B’s Core Sound 17 is a present cat-ketch example with two unstayed masts. The main and mizzen divide the cloth into separately controlled units, and the absence of an ordinary working jib removes a headsail-clew transfer from each tack. The mast loads return through the spars and their hull supports. That unstayed construction is a feature of this design; the compound name itself tells us the sail and mast allocation. Core Sound 17; designer Graham Byrnes on the cat-ketch.
An additional flying mizzen staysail can still be carried between the masts. It fills the space ahead of the mizzen, not the space ahead of the forward mainmast where an ordinary jib would work. The principal arrangement and the extra sail therefore describe different levels of the inventory.
Keep the working reason with the history
By the late nineteenth century, these choices belonged to working craft as well as yachts. Knight described ketches among British coasters and fishing boats; Day connected them with shallow, flat-bottomed craft in southern United States waters and with British coastal work. The same division of cloth could serve different hulls and trades. Their accounts show established use, not one proven origin of the arrangement.
Day’s own yawl example makes the handling choice specific. While another yacht stopped to reef, his crew kept their boat moving under jib and mizzen while reducing the main. He also reports that the other yacht beat them to windward the following day. The selectable after sail helped with one operation; the episode supplies no universal speed ranking. Day, pages 92–98.
Existing yachts could be rearranged too. The Herreshoff yacht Navahoe appears in a dated 1894 view with one principal gaff-rigged mast and forward sails, described in American usage as a sloop. A later view records her as a yawl in 1901, with a smaller main and a separate after mast and sail. These configurations show the physical redistribution; they do not establish why the owner chose it or prove a performance gain. Herreshoff catalogue, HMCo 429, including the dated image records.
Rig preferences could also precede experience. In The Cruise of the Snark, Jack London admitted choosing a ketch before he had sailed one. His enthusiasm tells us about a choice, while the attachments, available sail states and actual handling tell us what the arrangement can do. London, chapter I.
We have added a smaller, separately controlled group behind the main. Another division gives substantial sail to both masts, with the principal mast aft of the first. That changes the available working spaces again and brings us to the schooner.