Build your own 4.35 m beach catamaran with asymmetrical hulls and practical plywood, fiberglass and epoxy construction.
The SC 435 combines an approximately 120-hour build with self-aligning hull assembly. Designed for amateur builders, including those starting their first boat.
SC 435 specificatios
Principal dimensions and estimated construction time
Length
4.35 m
Beam
2.10 m
Weight
66 kg
Sail area
13 m²
Estimated building time
Approximately 120 hours
Hull construction
Plywood / fiberglass / epoxy
The SC 435 was my first catamaran design, drawn in 1979. Since then, customers in many countries have built and sailed it. The photographs on this page show actual boats and construction work by builders.
Watch the boats and construction method
SC 435 sailing video SC 435 sailing and construction photographs Asymmetrical hull construction video
SC 435 building plans: what you receive
The digital plan package is delivered by email attachment and includes:
An 18-page step-by-step building instruction ebook. 22 drawings. Additional information for the new rig.
For information sheets and the bill of materials, email Bernd at K-designs.
Order your SC 435 plans
US $70
Have a question before ordering? Contact Bernd directly about the plans and your project.
Questions about building the SC 435
It was designed for amateur construction. Each hull has only 10 parts, and the self-aligning matched-hole method avoids a separate jig. The supplied instructions explain the building steps.
Allow approximately 120 hours. Actual construction time depends on your experience, preparation and available working time.
The boat is designed for roof-rack transport and can be assembled and dismantled without tools. Check your vehicle and rack load limits, including the boat and all equipment carried.
The instructions and drawings are supplied digitally as an email attachment.
Email bernd@ikarus342000.com. Please mention the SC 435 and tell me what you would like to know.
Bernd Kohler · K-designs
Multihull building plans for amateur builders.
Multihull building plans for amateur builders.
© 2026 Bernd Kohler, K-designs. All rights reserved.
DESIGNED BY BERND KOHLER. DESIGNED IN 1979
SC 435 plywood/epoxy composite sailing catamaran
building plans
building plans
A builder’s SC 435 in Iceland: a design from 1979 with a continuing story.
EXPLORE THE BUILDING PLANS
Why build an SC 435?
Each hull consists of only 10 parts
Self-aligning assembly avoids a separate building jig
Standard aluminum tubes for masts and beams.
No tools are needed for assembly or after sailing.
Suitable for roof-rack transport.
Self-aligning assembly avoids a separate building jig
Standard aluminum tubes for masts and beams.
No tools are needed for assembly or after sailing.
Suitable for roof-rack transport.
How to build the plywood catamaran
The SC 435 uses a form of matched-hole construction inspired by aircraft assembly. Accurately positioned holes help the hull components align as they are joined, so a separate jig is not required.
The hulls are built from plywood with fiberglass and epoxy. Standard aluminum tubes for the mast and beams help keep the construction straightforward.
Some customers have completed their boats in four weeks of spare-time work. The estimated 120 building hours are a guide; your experience and working arrangements will affect the time required.
The hulls are built from plywood with fiberglass and epoxy. Standard aluminum tubes for the mast and beams help keep the construction straightforward.
Some customers have completed their boats in four weeks of spare-time work. The estimated 120 building hours are a guide; your experience and working arrangements will affect the time required.
Matched-hole construction illustrated on the DUO 480. This photograph demonstrates the method; it is not an SC 435 hull.
Hull components before assembly.
Hull construction progress.
From separate components to a nearly completed boat.
Built by amateurs. Sailed around the world.
The SC 435 was my first catamaran design, drawn in 1979. Since then, customers in many countries have built and sailed it. The photographs on this page show actual boats and construction work by builders.
An SC 435 off Terschelling,Netherlands
Sailing in Croatia
An SC 435 sailing in Finland
Watch the boats and construction method
SC 435 sailing video
SC 435 sailing and construction photographs
Asymmetrical hull construction video
SC 435 sailing and construction photographs
Asymmetrical hull construction video
Order your SC 435 plans
US $70
Have a question before ordering?
Contact Bernd directly <mailto:bernd@ikarus342000.com?
US $70
Have a question before ordering?
Contact Bernd directly <mailto:bernd@ikarus342000.com?
SC 435 building plans: what you receive
The digital plan package is delivered by email attachment and includes:
An 18-page step-by-step building instruction ebook.
22 drawings.
Additional information for the new rig.
For information sheets and the bill of materials, email Bernd at K-designs.
An 18-page step-by-step building instruction ebook.
22 drawings.
Additional information for the new rig.
For information sheets and the bill of materials, email Bernd at K-designs.
K-designs
Multihull designs for home construction. Copyright © 2026 B. Kohler, K-designs · All rights reserved
Multihull designs for home construction. Copyright © 2026 B. Kohler, K-designs · All rights reserved
Questions about building the SC 435
Is the SC 435 suitable for a first-time boat builder?
It was designed for amateur construction. Each hull has only 10 parts, and the self-aligning matched-hole method avoids a separate jig. The supplied instructions explain the building steps.
How long does it take to build?
Allow approximately 120 hours. Actual construction time depends on your experience, preparation, and how much time you have available.
Can I transport it on a car roof?
The boat is designed for roof-rack transport and can be assembled and dismantled without tools. Check your vehicle and rack load limits, including the boat and all equipment carried.
For even more information, go to the FAQ
How are the plans delivered?
The instructions and drawings are supplied digitally as an email attachment.
Is the SC 435 suitable for a first-time boat builder?
It was designed for amateur construction. Each hull has only 10 parts, and the self-aligning matched-hole method avoids a separate jig. The supplied instructions explain the building steps.
How long does it take to build?
Allow approximately 120 hours. Actual construction time depends on your experience, preparation, and how much time you have available.
Can I transport it on a car roof?
The boat is designed for roof-rack transport and can be assembled and dismantled without tools. Check your vehicle and rack load limits, including the boat and all equipment carried.
For even more information, go to the FAQ
How are the plans delivered?
The instructions and drawings are supplied digitally as an email attachment.
