LOA hulls                                     6.60 m without rudders
Beam c/c                                      3.00 m
Beam catamaran                                3.66 m
Beam on trailer                               2.50m
Draft hull/rudders                       0.25/0.54 m
Weight empty                                   380 kg
Weight CWL                                     840 kg
Parallel rig  sail area             15 x 2 = 30.00 m2
L/B hulls                                 1 : 13.7
Prismatic coefficient                        0.568
L/B ratio center line                          46 %
Construction time  about                     700 hours

Copyright     2017  by B. Kohler
           All rights reserved
US $ 238,-

The DUO 660 is a logical continuation of my other biplane catamarans.  We have the most experience with this rig from all designers who design for the amateur boat builder.
I use a bit a different system for road transport. The nacelle is turned on the trailer as shown. Transport width is then 2,5m.

The boat is a typical coastal cruiser/racer.  We use, as on all our trapezoidal cross section hull catamarans, the very effective anti-vortex panels as leeway presenters. For stability and speed prediction see diagrams.
Double click to editThe low draft of only 25 cm (rudders in up position) have the merit that you can reach coves which for other boats are unreachable. Beaching the boat is also much more easy.  The nacelle is big enough to seat four and sleep 3. A small pantry can be fitted as well. In one of the hulls a chemical toilet can be fitted.
If you use a cockpit tent the boat can sleep up to four persons.  If required foam  can be used in the front and back  to make the boat unsinkable.

As our other designs we use the ply(wood)/glass/Epoxy composite system.  This is  still the best system for a very light, cheap and easy to build boat. Here 3 photos from a DUO 660 under construction. For more information goto and FAQ

The photos are from a customer from Seattle. He has a very informative blog.
Study plan
including list of materials and some drawings
The plans are delivered as E-book
with building instruction
and 31 drawings plans
The drawings are computer generated CAD drawings
US $ 12,-