Designed for 55 years. A super fast catamaran for the first time amateur boat builder
The SC 435 was my first catamaran design. I designed the boat 1979. I lost count how many plans for this boat I have sold. The sail in almost any country of the world where is water. But the SC 435 story is going on. The last addition is the blue cat which was built in Island.
SC 435 has asymmetrical hulls and is build in a form of matched hole technique used in the aircraft industry. In this way the hulls are self aligning. There is no need for jigs etc. The hulls are plywood/glass/epoxy constructions. One hull consists of only 10 parts! Beams and mast are made from standard aluminum tubes to speed up construction and safe money. The boat is a perfect beach cat, very good to handle even in a lot of wind. No tools are necessary to set the boat up, or break down after a days sail. The boat is light enough for roof rack transport.
We have customers who have build the boat in 4 weeks of there spare.
The boat is not only fast, but also very seaworthy. First picture, a SC435, wind force 7 to 8 for Terschellingen, the Netherlands.
SC 435 has asymmetrical hulls and is build in a form of matched hole technique used in the aircraft industry. In this way the hulls are self aligning. There is no need for jigs etc. The hulls are plywood/glass/epoxy constructions. One hull consists of only 10 parts! Beams and mast are made from standard aluminum tubes to speed up construction and safe money. The boat is a perfect beach cat, very good to handle even in a lot of wind. No tools are necessary to set the boat up, or break down after a days sail. The boat is light enough for roof rack transport.
We have customers who have build the boat in 4 weeks of there spare.
The boat is not only fast, but also very seaworthy. First picture, a SC435, wind force 7 to 8 for Terschellingen, the Netherlands.
Length: 4.35 m
Beam: 2.10 m
Weight: 66 kg
Sail area: 13 m2
Construction time about 120 hours
Beam: 2.10 m
Weight: 66 kg
Sail area: 13 m2
Construction time about 120 hours
DELIVERY
The plans are delivered as E-book
with a step by step building instruction (18 pages)
and 22 drawings plus the new rig
as an attachment.
The plans are delivered as E-book
with a step by step building instruction (18 pages)
and 22 drawings plus the new rig
as an attachment.
Picture show with boats sailing and construction click arrow
Plans US $70.-
PDF INFO SHEETS with bill of materials
Sailing in Croatia
Video a-symmetrical hull construction
Copyright © 2025 by B. Kohler, K-designs
All rights reserved
MATCHED HOLE TECHNIQUE.
No need for a jig. The hull is self aligning
Example is from the DUO 480
No need for a jig. The hull is self aligning
Example is from the DUO 480