DIY inflatable catamarans: drawings, photos, reviews. How to make a homemade catamaran Homemade catamaran from 30 liter cans

A catamaran is a type of vessel that is made using two or more structurally integrated hulls. This type of watercraft is especially suitable for fishing, sports, tourism and entertainment purposes, gaining access to various hard to reach places. The sailing catamaran, reliable and safe thanks to its design features. Moreover, you can not only buy it, but also make it yourself.

Why make sailing catamarans with your own hands?

In addition to sailing ones, catamarans with a motor engine and with rowing pedal propulsors are common. They are also suitable for making on our own. Especially if you take into account the fact that buying a ready-made catamaran costs several times more than the cost of making it yourself. But many start building a catamaran on their own not so much out of savings cash, how much because of the desire to express in your brainchild original author’s ideas regarding the shape, design, constructive solutions, achieving certain qualities of the vessel that are not available in the proposed industrial or other designs available on the market.

In any case, no matter how difficult the work of building sailing catamarans with your own hands may seem at first glance, this is a very real and achievable task for a person who is more or less skilled and has skilled hands. Therefore, below we will look at the main stages of building a sailing catamaran. Precisely sailing because it does not have to be subject to mandatory registration with the State Inspectorate for Medical Information (GIMS), which is required for almost any small boat with a motor engine.

Choosing a catamaran design

The first thing you must decide when starting to build a catamaran is to choose its basic design, namely, what its hulls will be made of. They can be made of plywood, boards, water bottles, pipes, etc. A great advantage is the sailing inflatable catamaran, the float hulls of which are made of rubberized material. It is this design that allows you to get a collapsible sailing catamaran.

Design requirements

The design of a catamaran depends significantly on the purpose for which you are building it. It’s one thing to use it for recreation and fishing on a small quiet lake, quite another thing to raft it down a stormy mountain river. The requirements for the strength of the structure and its elements in these cases are radically different. The ratio of the weight of the vessel and its carrying capacity is also important. After all, the smaller it is, the easier it is to transport the vessel to the place where it is intended to be used. In terms of this indicator, there is no equal to an inflatable collapsible catamaran, for which the weight of the vessel per one crew member ranges from 4 to 10 kg, and for inflatable kayaks - 8-11 kg.

Catamaran project

Real projects exist and are available that can be implemented in conditions small apartment, using only hand tool, providing high mobility products (no parts longer than one and a half meters - can be transported free of charge in any public transport and on an airplane), its low weight, ease of assembly and disassembly of the structure, the necessary strength and reliability.

So, if you have finally decided to make a collapsible sailing type, then you should look in the specialized literature for drawings of sailing catamarans that correspond to your choice. Believe me, it's not that difficult.

Let's consider a sailing catamaran based on two inflatable rubberized bags, which when inflated form two “cigars” with a diameter of 40 cm and a length of 280 cm, weighing 12 kg with sails and oars, which can easily support four crew members, providing them with sufficient comfort for work and rest and fishing. Each crew member accounts for only 3 kg of boat weight, and the ship’s unsinkability, convenience and excellent navigability have been tested in practice by dozens of short and long trips along the rivers and lakes of the central part of European Russia. These trips have shown that a catamaran design based on bag-type floats, which easily change their shape, overcomes obstacles and shallows much more safely, where kayak-type structures based on a rigid frame often damage the rubberized fabric, forcing repairs in the field.

Float cylinders

The main thing is to make bag-shaped cigar-shaped (inflated) float cylinders. To do this, we take “500” fabric - very durable, light and dense, with the common name “serebryanka”, since it is equipped with a special aluminum coating. We cut out the parts of the cylinders from two pieces of fabric measuring 300 x 64 cm (two per cylinder - the lower and upper parts) and glue them together with ordinary rubber glue. If there is no source material suitable size, then first we glue together such pieces from smaller pieces. We glue them together with an overlap of at least 2 cm. Subsequently, we additionally glue the resulting seams with strips of the same or less thin fabric with an overlap of 2-3 cm, first from the inside of the cylinder, then from the outside. In advance, we glue tubes with flanges for inflation from the inside of the cylinder so that the tube in the upper part is directed inside the structure of the catamaran, ensuring convenience when inflating. Lastly, glue the rear, wider part of the cylinders together, following the example of a bag of flour.

A finished balloon (not inflated) made of such fabric weighs about one kilogram. For a more durable design, cylinders can be made from so-called gas holder fabric, which is used, for example, at metallurgical enterprises in containers for storing oxygen reserves. Cylinders made of this fabric are twice as heavy, but also many times stronger than those made of silver.

Deck

The design of the sailing catamaran provides for the presence of two float cylinders made of rubberized fabric, which are combined by rigid elements available only in the upper part of the structure. They are a bolted platform (to simplify assembly) of four longitudinal slats or pipes (two per float) and four to six transverse beams. It is advisable to make the longitudinal slats from the main part up to 150 cm long and the extendable part (up to the total length of the slats up to 220 cm) from a duralumin channel. Cross beams with a length of 110 to 150 cm are made from material available to you, for example, from duralumin tubes with a diameter of up to 30 mm. The float cylinders are fastened to the platform using strong tapes (gross straps), three per cylinder, or with cables using special linings with eyelet holes glued to the cylinders. On top of the resulting platform, three air-filled swimming mattresses are tightly secured with cables - one in the bow and two (on top of each other) in the stern. The rowing crew members sit on these mattresses. They provide convenient accommodation for the crew and additional buoyancy of the vessel in the event (although this never happened) one of the floats is damaged. Under the mattresses, it is advisable to strengthen diagonally located ties and a sheet of durable fabric so as not to wet the cargo on the deck.

Steering

The catamaran is controlled using a rudder mounted on the aft transverse beam, made from a piece of duralumin plate measuring 23 x 48 cm. The fastening is carried out with a bolt and a wing nut, limiting the movement when raising and lowering the rudder with screws, a tiller and a line (a cable for raising the rudder in small places). To prevent yaw when oaring, there is a small centerboard on the bow crossbeam, which is not needed when sailing. The steering wheel is collapsible with a removable feather.

Mast, oars and sails

It is best to make a mast from three duralumin tubes inserted into each other. Although a possible option is made of wooden rods with connecting strips. When carrying a vessel, other elements of the spar are inserted into the long parts of the mast - a gaff and a composite boom, made from duralumin or tubes of the same diameter. The mast base is fastened in the middle of the second beam, as well as by four cables with tensioning devices from the upper end of the mast to the ends of the first and third transverse beams.

The oars are also made composite, like those of a canoe.

The sailing catamaran is equipped with sails made of feather percale; they normally consist of a mainsail and a jib, total area- 7 sq. m. Such sails, installed on a mast with a total height of 360 cm, complemented by a jib, allow the catamaran to pick up speed up to 8 km/h in favorable winds. If desired, the sailing rig of the catamaran can be increased by experimenting with your own navigation experience.

Having made all the elements of the catamaran, inflated the floats and mattresses, assembled and adjusted the deck, mast, rudder and sailing equipment, you will get the result: a sailing catamaran made with your own hands is ready for use and is eager to set sail to reward you and your companions with dignity for your efforts.

In this article we will tell you how to make a sailing catamaran with your own hands. Let's say right away that the simplest catamaran for relaxing on a lake or river can be made from available materials, tightly knitting materials that float well. A homemade catamaran made from bottles is a fun design that will last a couple of days and make your weekend unforgettable.

In this article we offer more difficult option homemade catamaran. Advantages of this design:

The main material is pine wood: available to anyone;
one person can assemble and transport;
spacious deck

Such a building can last for more than one season and, if assembled correctly, can replace a boat or fishing boat. Let's go directly to step by step instructions, which will help you make a catamaran with your own hands.

Frame

The main material is pine (high-quality, dry).

The frame is made up of 8 beams: 4 stringers and 4 beams (transverse).

Each one consists of two parts. Parts different lengths: in the places where they are connected, they are attached with sub-connections (the length is selected individually - to suit the “rower”). Next you need:

Plane the bars - 8 pcs. (40x40). The length of 4 of them is 1110, 4 – 1340.
Connect the parts of the stringers with the corners (40x40x4) so that the middle of the corner falls on the joint of the parts. There must be a gap at the joints of the parts!
Plane the bars – 4 pcs. (75×30 x1380). Narrow the ends to reduce weight. Place the beams on the stringers and drill.
Underjars – stern (45x23x770) and bow (58x24x1010). The optimal fastening of the undercuts to the beams is a nail.
Sand the wooden parts well and cover with drying oil.

Deck

Material – tarpaulin (the densest).

By adding allowances for pockets to the length of the frame, you get the length of the deck panel. An allowance is needed for the pockets for the frames.
We calculate the width by measuring the distance between the third and second stringers. Leave enough allowance for hem folding.
Form pockets for medium beams. To do this, sew wide strips from the bottom.
The holes for the bolts should be covered with a harsh thread.
When attaching the beams to the stringers, make sure that the deck is taut.

Lockers

Materials: plywood (3 – 4 mm), wooden slats(20×15), glue, piano hinges (fastening the lids), screws.

Any thick fabric is suitable for the cover.

Precise adherence to their dimensions is necessary so that the bow locker can be easily inserted into the stern locker, simplifying transportation. Handles stretched through the holes in the sides of the smaller locker will be convenient.

Larger dimensions: 800x285x225 mm.

Oarlocks

Can be made from steel rods (14 mm diameter is sufficient).
Cut the rods along the axis to a depth of 7 cm and bend the “horns” to the sides.
The swing axis will replace the nail (4 mm), the fishing line will act as cotter pins.

Sub-clavicle

Material: aluminum pipe (diameter 22)

- First, flatten the ends of the pipe.

Inserts - plates (aluminum, thickness 7).

Attach them vertically to the corners of the stringers (first and fourth).
Attach hingedly, but tightly (rivet).
In a similar way, attach pipe struts (diameter 20) to the shelves. An aluminum plate clamp will do.

Floats

Material: thick tent fabric, rubber balls.
Balls are inserted into the slots of the sewn float balloon.
Dimensions: length – 3600, diameter – 400.

During production:

Leave a hem allowance (40) and a seam allowance (60).
To give the float the desired shape, cut out 4 stern and bow wedges (length 760).
Attach safety straps (for balloons) to inner surface balloon. You will then tie the ribbons from the ribbons onto the stringers.
Leaving holes in the stern and bow for the balloon tubes, sew the edges together with strong thread.

Mast

The design of the mast directly depends on the sail model. Therefore it is necessary select after purchasing the sail. Let's just say that this catamaran will “feel” great with a 4-meter mast. It is better to make it collapsible - three sections.

Geek

Workpiece: block 30×30

The mast manufacturing technology is repeated.
Front end hinges are steel strips.
Drill holes to connect to the swivel.
Provide the rear end with pads for docking with the butt.

Knock

The manufacturing technology is repeated. Last step: equip the leg with a wire duck and a metal pulley.

Sail

Sewing sails is a special art! If you have no experience, experts advise equipping your brainchild with a ready-made sail. A sail with an area of 4 m2 can provide decent speed and sufficient safety of such a design. If necessary, you can make a simple structure from finished fabric.

Pul

Main materials: pine (bars), plywood 10, steel cable, sheet steel 1.7.

The stand with the rudder components is pulled through a corner to the frame (the horizontal shelf of the same corner is secured with screws). Additionally equip the rack cable braces.

Connect the rudder post and the stock shaft with corner loops. Pass the wire turning axis through their holes. From three plates (each thickness is 1.7) you can rivet the movable part of the stock.

The rotary pen is prepared from a sheet of 1.5 duralumin.

Centerboard device

Make a beam from corners (duralumin) measuring 35×35 and 30×30.
Carefully saw through the holes for the bracket suspension tenons.
The bracket can be riveted from several profiles.
Make guy wires from 2 mm steel cable, rings and pieces of copper tube.
To cover the centerboard, take a 2 mm duralumin sheet.
Select the groove at the bend with a round file with a diameter of 5 mm.
Rivet the “tail” part. Using plywood pads, reinforce the centerboard and insert a console (made from a vaulting pole).
Connect the casing to the console with rivets.
Glue the foam fairings into the daggerboard, after wrapping them in gauze soaked in epoxy.
Connect the centerboard with the bracket pivotally.

All dimensions are given in millimeters.

Post Views: 2,565

Fishing becomes comfortable and effective when using swimming devices that allow you to fish anywhere in the river and quickly move around the reservoir. Catamarans for fishing are especially popular among lovers of quiet hunting.

The advantage of a catamaran is: light weight design, it can be transported by passenger vehicles. Inflatable models are packed in a special backpack, and the non-disassembling parts are secured to the roof of the car. The models are characterized by easy movement at any speed and stability on waves.

A popular means of fishing is motorized fishing catamarans. It allows you to expand the range of fishing spots, you can choose the best sites for biting. Assembling and disassembling the catamaran can be done by one person: its parts are assembled within half an hour, which makes the device mobile and convenient.

The deck is half a meter higher than the water surface, which saves fishermen from the waves, and rainfall does not accumulate inside the frame. There is no need to bail out the water; it drains into the gaps of the deck, making the catamaran easy to wash. From below, inflatable catamarans are protected by a beam from rubbing against the surface of the bottom or shore of a reservoir.

The main advantages of a catamaran-type vessel are:

high frame stability;
spacious and high deck;
high load capacity;
durable bottom;
large air compartments;
easy assembly and disassembly;
easy care and cleaning from dirt;
safety of use.

Specifications

The catamaran consists of two air cylinders and a frame, which can be inflatable or rigid, made of aluminum. When assembled, the entire structure fits in a backpack, which is convenient for transportation.

The weight of the craft often does not exceed 20 kg. Motor catamarans are heavier because they have more solid foundation, but their designs also use lightweight materials. The dimensions of the products are different, they reach a length of 4-6 meters.

Sustainability

The catamaran is a stable structure; it easily rides the wave, receiving a minimum of impacts. Spray formation is small at any speed, which is comfortable for passengers. With a wave height of 0.5 m, the stability of the structure is superior to other models. Catamarans are stable on course and easily maintain a given trajectory.

The watercraft is able to withstand the influence of external forces, its lateral stability resists the forces of the turning moment. Longitudinal stability resists piles on the stern or bow - a longitudinal turning moment (turning over the stern). The large distance between the cylinders and proper weight distribution increase the stability of the product.

The safety of a catamaran is greater than that of boat models. The stability of its structure is much higher. Boat overturns are possible when there is a load on board, which often happens when fishing for fish when the craft rolls. Using inflatable structures, even several people can be on the same board without the danger of it tilting or capsizing. This craft cannot be capsized or sunk.

Usable space

Catamarans are much wider than monohull models, making them usable space almost twice as much as boats. Decks with a width of 2 m can be from 2.5 to 4 m long; an awning or tent is installed on a large area.

Fishermen place a table and chairs (armchairs) on the deck area, as well as fishing equipment and everything necessary for the trip. The deck is of sufficient size allowing you to move freely inside the catamaran. The models have a comfortable tension or rigid deck that can accommodate from 2 to 10 passengers.

Economical

Due to their design, catamaran models have reduced drag. Their weight is divided between the air hulls, creating little drag compared to boats. The speed of a catamaran is 20-40% higher than that of a boat with the same load.

Catamarans accelerate to 20-25 km/h when using smaller engines that consume little fuel. The fuel consumption of these models is one third lower than that of boats. Fishing models have a transom for a motor up to 10 hp, but they often use small engines from 2 to 5 hp.

Load capacity

A loaded craft can dive below the optimal depth, but overloading a catamaran will only worsen its speed characteristics: for it to sink, the cargo must be three times its carrying capacity. This means that with a carrying capacity of 500 kg, an overload of up to 1500 kg will be critical for this craft.

Catamarans have a carrying capacity of 300 to 500 kg; the load does not affect its stability and speed. Despite light weight, the models have a large carrying capacity; they can accommodate boxes for transporting catch, fishing equipment and many other necessary loads. Number of passengers - from 2 to 10 people. Unsinkability under overload is a big advantage of the catamaran design compared to boat models.

Maneuverability

The maneuverability of a vessel is its agility when maneuvering to the right or left of the geometric center of the structure and the possibility of reverse movement. Catamaran structures have good maneuverability—quickly turning and returning to their original position. The raised bow and stern increase the maneuverability of the vessel.

Types of catamarans

Types of catamarans differ in technical solution parts of the vessel:

deck arrangements;
installation of transverse beams for floor rigidity (beams);
supports different heights.

With flexible and rigid locker

The description of catamarans contains information about materials for deck construction. The locker of a catamaran can be flexible or rigid. Models with a flexible locker are easier to stack during assembly and transportation, while rigid structures are more reliable and convenient to use, but take up a lot of space during transportation.

The tension deck is made of PVC fabric, lined around the perimeter with slings with loops for fastening to the frame. The boom of these catamarans is of medium thickness, the air valve is near the stringer, and the fasteners are cross-shaped. Flexible types use polyvinyl chloride (PVC) material with high density— 800 g/sq.m. Large cylinders can be installed on these models.

Rigid locker structures are made of boards, plywood and other dense but lightweight materials. Two supports are attached under the model, the cylinders are located with different sides stringer, density of PVC materials used - 700 g/sq.m. The supports are attached above the firmware, the air valves - above the boom. There are options with stockers, the cylinders in which are installed above the boom. On vessels with a rigid locker they fish in shallow water.

Models for two and three beams

Catamaran models for fishing have two or three beams that serve to strengthen the structure. The higher the protection of the frame, the greater the passenger capacity and other technical characteristics.

Models with two beams - for two passengers. The supports are installed at a low height. Load capacity - up to 300 kg, vessel length - up to 3.4 m, stringer diameter - 1.3 mm, cylinders - rubber patches, fastening - in the form of crosses. Can be equipped with flexible lockers. These designs are in demand among fishermen.

Catamarans with three beams are four-seater. Load capacity - up to 500 kg, air valves - near the stringer. The lockers are hard, sometimes the boom is made of rubber. Vessel options with two legs are popular. These flotation devices are made of high-density materials.

With low and high support

Supports of different heights affect the installation of motors of different power. Small models have low technical parameters, large vessels with powerful engines - higher quality characteristics.

Models with low supports are designed for installing low-power motors. Their carrying capacity is 300 kg, the air cylinders have a small diameter. It is possible to use rubber booms and ballers. The stringers are attached to PVC pads.

To use powerful motors, catamarans with high legs are produced. These models feature a rigid aluminum frame, large-diameter cylinders (density 800 g/sq.m.), and 1.4 mm thick stringers. The supports are additionally secured with braces. The length of such a catamaran reaches 4 meters.

Inflatable catamarans

When moving, the inflatable catamaran comes into contact with the water only with its cylinders; the deck and frame remain above its surface. This reduces water resistance and increases speed. Nowadays, balloon chambers with high pressure(250−300 mbar), in the manufacture of which reinforced PVC materials are used.

The use of single-layer cylinders made of durable materials reduces the weight of the craft and increases their rigidity. Inflatable catamaran models expand the capabilities of fishermen; with their help, users of a collapsible vessel get into the most inaccessible places of the reservoir, delivering the craft to the shore using personal vehicles.

How to build a catamaran with a motor with your own hands

Only a good craftsman can construct such a craft on his own. But sometimes a do-it-yourself catamaran becomes better than the factory version; the owner has the opportunity to adjust the parameters and characteristics of the vessel to his needs.

At first future model is designed: its detailed drawings are created, after which general drawing is divided into separate drawings of all parts of the vessel. Then a frame is made (usually from duralumin). The next stage is the production of air cylinders from durable PVC of specified dimensions (length 3.5-4 m). The cylinders are equipped with valves for air injection.

IN homemade version You can install the stock with tension. The assembly of the structure is completed by installing the stringers and deck. Important stage design - checking all parts of the craft for reliability. Special attention You need to pay attention to the tightness of the air cylinders. A high-quality homemade catamaran is always the pride of the owner.

With your own hands? For such a vessel you need two main elements: a frame and air tanks.

Frame. IN hiking conditions frame catamaran can be made from wooden poles, which saves weight and volume of equipment. In other cases, it is made of duralumin alloy. IN industrial production They use D16T aviation grade aluminum - this is a rather expensive material, it is difficult to obtain, especially in small quantities. Moreover, the pipes should have a diameter of 35-40 mm with a wall thickness of 1.5 mm.

As an alternative, a cheaper AD31T1 alloy is suitable, but this frame is better used for catamarans that will be used on simple rivers.

Cylinders. Manufacturing of cylinders complex process because it requires some experience. You will need a pattern, PVC fabric itself, glue, an additive for glue and tools (hair dryer, roller, special spatula). I can immediately assure you that the first cylinders, like pancakes, are lumpy :) Therefore, it is better to order production, or buy factory ones. If you still decide to self-production, then our recommendations are:

1. PVC fabric any, but only boat. Density from 750 g/sq.m. Very good fabric produced by Mirasol, it is used to prepare cylinders for Khatanga kayaks.
2. Glue. Better in terms of price-quality parameters, this is glue 900 I. There is detailed instructions by application. It will take 1 liter jar with reserve
3. Additive. Desmodur (the Chinese equivalent is cheaper). Needed to be added to glue, it gives thermoplasticity, your balloons will not fall apart at a temperature of 70 degrees, but do not leave them inflated in the sun.
4. Patterns. Below you can take the pattern and print it on a large format printer. Based on this model, the catamaran in the example above was made, 4 meters long, with a cylinder diameter of 45 cm.

5. High pressure valves - you can buy them at the market where they sell PVC boats.
6. You also need tools such as a hair dryer, a brush, a roller for smoothing the fabric and a spatula (can also be purchased at a market where they sell boats or repair them).
7. Sling, eyelets and fittings

In our online store you can purchase entire cylinders or catamarans.

Several videos show how the master, the Author of the channel “Alexander Sedoy,” conceived and implemented the idea of building a high-quality catamaran from polystyrene with his own hands. The task was set, the swimming device should be:
1. Unsinkable.
2. Indestructible.
Z. Cannot turn over.
4. Foldable, with the ability to be transported on the trunk
small passenger car.
5. Decent dimensions for comfortable swimming.
b. The draft is half that of a kayak.
7. Lightweight, each part should not be heavier than 20 kg.
8. Get ready quickly and easily.
9. Roomy.
10. Lifting capacity, not less than 700 kg.
11. Autonomous, several sleeping places, place for fishing and barbecue.
12. Possibility of installing a motor up to 10 p.s. on a catamaran.

Selection of float material.
First I bought penoplex “Comfort”. Width 100 millimeters. I bought a package. Weight 18.7 kilograms. Cubic capacity 0.28.
Ultimately, the master settled on URSA. Noble material, pleasant, comfortable to work with. Thickness 50 millimeters. The weight turned out to be 15.7 kilograms. Cubic capacity 0.3. The cost of one package is 1200 rubles. The weight of 1 leaf of ursa is 1.1 kilograms. Why 50? I read that, of course, it’s easier to glue a weave, 2 times faster, but the more intermediate layers - stiffening ribs, the stronger the catamaran structure. Therefore, I settled on a sheet width of 50 mm.

The purpose of the catamaran is to sail together with the kayaks. Therefore, the draft should be no more than 3-5 centimeters. The kayak has up to 15 - 17 centimeters. Maximum comfort for fishing. The structure must be completely dismountable, each part no more than 2 meters long. As easy as possible.

First, let's prepare a device for cutting edges. Nichrome thread will be used. At the same time, the walls are baked, they become smooth. Extra rigidity and moisture resistance will not hurt. You will need exactly three packages of materials. 50 x 125 x 600.

The most important thing is that the spiral is securely fastened, otherwise the size will float away. If the spiral is held clearly all the time, all the details will be exactly the same. Smooth adjustment of “light attenuation” occurs with the help of a 220 to 5 volt transformer. The device cuts the material like butter, but it is important that the thread does not get red hot. The voltage supplied is 1.5 and 2 volts. With manual feeding, ideal boundaries are unlikely to be achieved. But this is not required. The work takes place without dust, noise, quite smoothly and neatly. URSA material must be fed smoothly.
The master showed how the cuts differ nichrome thread and factory.

Now cut it exactly in half without stamps. If the spiral does not heat up red-hot, the material does not give off any odor. The device works great. Why is the cut done in half? Because I decided to make it not transverse, but longitudinal. Thanks to this there is no waste. Except for the edge. The edge is cut to length on both sides. The side edge is cut from only 12 sheets out of 24. Another advantage: no stamps are needed. It became possible to increase the length of the catamaran by 1 meter. I had to buy three more sheets, so I ended up with three packs and four sheets. Total 24 sheets. Additional 100 kilogram displacement. Reducing draft and increasing speed. Simplification of product installation. Ideally smooth and even surface. Saves putty and glue several times. Reducing work by an order of magnitude. Much better in strength than a cross set. Longitudinal set in a checkerboard pattern.

The second part of the video is about the construction of a homemade catamaran. The float panels are joined together on each side. The blanks are treated with waterproof products.

Part 3 is about building a catamaran from polystyrene.

Part 4

We are waiting for the final 5th part with tests of a homemade catamaran on a pond, which the author will post, presumably, in the spring or summer.