A boat capable of being assembled, disassembled and transported by one individual and without any tools or special equipment. The boat comprises a superstructure which is substantially of lightweight buoyant material such as foam board, and which includes a pair of ski-like hulls, a longitudinal member removably attached to each hull, and a pair of transverse members removably interconnecting the hulls in spaced relation. A cockpit area is provided between the hulls and transverse members. The superstructure is preferably composed of only three components employed in pairs; the hull members, the longitudinal members, and the transverse members. Each of these components are preferably die cut from the same material, and each component of the superstructure has joint elements integrally formed therewith for interconnecting the components. When used as a sailing craft, a mast is removably attachable to the superstructure and to which a sail assembly is rigged. A rudder is removably attached to the aft end of each hull and a daggerboard can be removably installed in each hull. The boat can also be used with paddles or with an outboard motor.

FIELD OF THE INVENTION 
This invention relates to boats, and more particularly to small sailing or 
other boats of disassemblable construction. 
BACKGROUND OF THE INVENTION 
Constructions are known for providing a boat which can be assembled and 
disassembled for ease of transport. One well-known type is the inflatable 
boat, in which the hull is formed of one or more inflatable compartments. 
Another type is a foldable boat construction which employs a frame of 
relatively rigid elements which can be assembled and disassembled, and 
over which a fabric or other skin is affixed as the outer hull material. 
This latter type of boat is available, typically, as a canoe or canoe 
sailboat. Another known boat construction utilizes assembled sections 
which are fastened together to form the hull. Also known is the so-called 
board boat of which some are constructed of a single hull, somewhat like a 
surfboard, and which is of rigid plastic or foam construction. 
SUMMARY OF THE INVENTION 
In accordance with this invention, a knock-down boat is provided which is 
of extremely lighweight construction and which can be readily assembled 
and disassembled without tools by one individual and which, when 
disassembled, can be readily carried by one individual. The boat comprises 
a superstructure which is substantially of lightweight buoyant material 
such as foam board, and which includes a plurality of ski-like hulls, a 
longitudinal member removably attached to each hull, and a plurality of 
transverse members removably interconnecting the hulls in spaced relation 
and which also serve to support a cockpit area or surface. Each of the 
components of the superstructure are preferably die cut from the same 
material, and each component has integrally formed therewith the joint 
elements for interconnecting the components. 
The boat may be used as a sailing craft, or with paddles or an outboard 
motor. For sailing, a mast is attached to the superstructure by a fitting 
provided thereon, and a sail and spar assembly is rigged to the mast by 
any convenient means. Each hull has a rudder pivotably attached to the aft 
end, and may have a daggerboard removably fitted therethrough. A mounting 
bracket can be attached to the superstructure for attachment of an 
outboard motor.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings, there is shown a knock-down boat in accordance 
with the invention, which comprises first and second hulls 10 and 12, each 
of ski-like configuration having an upwardly curved forward end 14 and 
constructed of foam board or other lightweight buoyant material. First and 
second longitudinal members 16 and 18, each of identical foam board 
construction and configuration, are fitted to respective hulls 10 and 12 
and are interconnected by a forward transverse member 20 and a rearward 
transverse member 22, each also of identical foam board construction and 
configuration. The longitudinal members 16 and 18 each include downwardly 
extending tabs or joints near the forward and rearward ends and which are 
cooperative with respective openings 26 in the associated hulls for 
joining each longitudinal member to the respective hull. Each tab or joint 
24 in the illustrated embodiment is of split symmetrical configuration in 
which the halves 28 are resilient to be squeezed together for insertion 
through the associated opening 26 in the hull and, after full insertion, 
to spring apart such that the oppositely extending lip portions 30 lock to 
the underside of the hull. The forward transverse member 20 includes 
respective slotted openings 32 which are cooperative with the slotted 
confronting portions 34 of the longitudinal members 16 and 18 to interlock 
both longitudinal members to the forward transverse member, as 
illustrated. The ends of the transverse member 20 are sufficiently 
resilient to be pulled apart sufficiently to be fitted over the 
longitudinal members in order to engage the slotted portions of the 
longitudinal member within the opening of the transverse member. The 
rearward transverse member 22 has similar openings 36 which are 
cooperative with the confronting slotted ends 38 at the rear of the 
longitudinal members 16 and 18, and these components are similarly engaged 
as the forward transverse member and longitudinal members. Flanges 92 can 
be provided at one or both ends of the transverse members to secure one or 
two oars or paddles 94. Aligned openings can alternatively be provided in 
the transverse members for storage of one or more oars or paddles. 
The hulls 10 and 12, longitudinal members 16 and 18 and transverse members 
20 and 22, are each preferably die cut from the same foam board material. 
The foam board material is typically 4 pound polyethylene foam, about 2 
inches thick, and may be of uniform composition or of laminated 
composition. The bottom layer of a laminated board can be of more highly 
abrasion resistant material than the core material to lessen wear in the 
event that the bottom hull surfaces engage rocks or a sandy floor. The 
board material can be colored for aesthetic appeal or may have one or more 
colored outer layers over a core of contrasting color. For greater 
buoyancy, the hulls can be of thicker and/or less dense material than the 
other constituents of the superstructure. 
The curved forward ends 14 of the hulls 10 and 12 can be formed by 
providing a series of parallel slices partially through the foam board and 
cementing the sliced portion in the curved position using a suitable 
adhesive such as a Neoprene resin modified rubber cement. The curved ends 
can alternatively be formed by a turnbuckle or other tension means which 
can be adjustable to produce the desired forward end configuration. As 
shown in FIG. 8, the turnbuckle 100 is secured at one end to the hull by a 
plate 102 on the underside of the hull, and at the other end by a hook 104 
attached to the forward corner joint 46. 
A pipe frame 40 is provided as shown and is composed of plastic, aluminum 
or other suitable pipe sections 42 which are retained within openings 44 
near the corners of the transverse members 20 and 22. The forward and 
rearward pipe sections 42a and 42b are connected to elbow or corner joints 
46 which are removably secured to the longitudinal pipe sections 42c for 
assembly and disassembly. A trampoline 48, formed of canvas or other 
suitable sheet material, is secured to the longitudinal pipe sections 42c 
by side sleeves 50 through which the longitudinal pipe sections are 
disposed, and lies within the area between the longitudinal pipe sections 
and transverse members, as illustrated. A fitting 52 is provided centrally 
of the forward transverse pipe section 42a to which a mast 54 can be 
connected. Spars 56 and 58 are connected to the mast for retention of a 
sail 60. If desirable, fasteners can be employed to secure the pipe 
sections. For example, locking pins can be inserted through aligned 
openings in the corner joints and pipe ends, or threaded set screws can be 
provided in the corner joints. Fasteners can also be provided in the mast 
fitting 52. The pipe sections can also be threadably attached to the 
corner joints. 
A daggerboard 62 is fitted through a slot 64 in each hull and is secured at 
the upper end to the confronting longitudinal pipe section by a curved end 
66 fitted over the pipe section and the covering sleeve of the trampoline. 
Alternatively, a portion of the sleeve 50 can be removed to allow 
attachment of the daggerboard end 66 directly onto the pipe section 42c. 
The daggerboard is preferably disposed to abut the inner side surface of 
the longitudinal member for improved lateral support. For some sailing 
applications, the daggerboards may not be needed, and are not usually 
needed for rowing or motor propulsion. 
A pair of rudders 68 are provided outbound from each aft end of the 
respective hulls, and each is pivotally connected to the respective hulls 
by a convenient hinge or coupling such as a pintle 70 (FIG. 7) attached to 
rudder 68, and coupled to a gudgeon 72 attached to a bracket 74 which is 
affixed to the respective longitudinal members 16 and 18 by fasteners 75 
extending through the bracket and member. Each rudder has affixed thereto 
a tiller 76, and the two tillers are interconnected by a cross-rod 78 for 
operation of the pair of rudders in unison. The rudder and daggerboard on 
each side are, in the illustrated embodiment, aligned on a common 
longitudinal axis and have the same shape at the below-water portion. The 
rudders and daggerboards are typically made of aluminum. The mast and 
spars are also typically of aluminum. The tillers and cross-rod are 
typically of wood or aluminum. 
The spars and sail assembly are of lateen design in the illustrated 
version. The upper spar 56 is rotatably secured to the top of the mast by 
an uphaul line 80 which is secured to a cleat 82 near the bottom of the 
mast. Instead of a cleat 82, the line 80 can be secured to pipe section 
42a. The lower spar 58 is rotably secured to the mast such as by a ring 
fitting 84, and the two spars are hinged such as by a ring fitting 86 at 
the confronting ends. The sail is fitted to the spars by any convenient 
means. For example, the spars can be fitted through pockets provided along 
the sail edges, or the sail can be attached to the spars by rings or other 
appropriate fittings. A main sheet 88 is rigged to the sail such as via a 
pulley 90 provided on the lower spar for sail adjustment in well-known 
fashion. 
An alternative frame structure is shown in FIG. 9, and includes front pipe 
sections 106 of inverted V-shape and joined by an elbow 108. A boom 110 is 
pivotably attached to elbow 108 such as with a ring fitting 112, and a 
loose footed sail 114 is secured to the boom by ring or other suitable 
fittings. Other sail configurations can also be employed for specific 
implementations. 
The boat can be employed other than as a sailing craft. The boat can 
accommodate an outboard motor mounted on a bracket 120 attached to rear 
pipe section 42b, as shown in FIG. 10. The bracket includes rail supports 
122 secured to pipe section 42b, and to which a plate 124, typically of 
marine plywood, is affixed. An outboard motor is attachable to the plate 
in usual fashion. The boat may also be paddled. 
For assembly of the boat, the longitudinal members 16 and 18 are each 
snapped into the openings of the associated hulls 10 and 12, and the 
transverse members 20 and 22 are respectively snapped onto the confronting 
portions of the longitudinal members to provide the superstructure of FIG. 
2. The pipe frame 40 is then fitted to the trampoline and the transverse 
members, and the pipe sections 42 interconnected to complete the frame. 
The trampoline may remain attached to the pipe sections 42c, and these 
sections can be manipulated onto the transverse members during assembly. 
If employed, the rudders 68 are then fitted to the respective hulls by 
means of the pivotable connectors, and the daggerboards 62, if used, are 
inserted through the respective slots 64 in the respective hulls over 
respective pipe sections 42c. For sailing, the mast 54 is secured to the 
fitting 52, and the sail assembly then secured to the mast. Alternatively, 
the mast, spars and sail can remain as a unit and, after the mast is 
installed in the mast fitting, the sail can be unfurled. 
For disassembly, the reverse procedure is employed. The sail is furled and 
the mast removed from its fitting, and the rudders and daggerboards are 
then removed. Thereafter, the pipe frame is disassembled and removed from 
the transverse members. The transverse members are then pulled out of 
locking engagement with the longitudinal members, and the longitudinal 
members are pulled out of locking engagement with the associated hulls. 
The foam parts of the superstructure can be readily bundled into a small 
package which can be carried in a canvas or other bag or otherwise tied or 
secured. The bag can also contain the other boat constituents, including 
the rudders, daggerboards, mast and sail assembly. 
The boat can be constructed of any convenient size. In one present 
embodiment, the boat is about 7.5 feet in hull length, and the trampoline 
cockpit area is about 3 feet wide and 4 feet long. The hull members are 
each about 22 inches wide. The longitudinal members are about 6.5 feet 
long, and the transverse members are about 4.5 feet long. The trampoline 
is about 16 inches above the top surface of the hull members. The pipe 
frame is of 2 inch aluminum tubing, and the rudders and daggerboards are 
of 3/16 inch aluminum. The superstructure weighs about 10 pounds, and the 
pipe frame and mast weigh about 10 pounds. The boat is therefore extremely 
lightweight and can easily be carried by a person when disassembled. The 
boat can be conveniently boarded by stepping on one of the hull members 
with one foot and climbing onto the trampoline with the opposite leg. The 
boat can be of various sizes to suit the user's requirements. For 
relatively long sizes, the hull and longitudinal members can be hinged or 
jointed so that the disassembled length can be of convenient length for 
stowage and carriage. 
The invention is not to be limited by what has been particularly shown and 
described, except as indicated in the appended claims.