guide to make boat

Following on my previous post about a big catamaran, here is the other extreme. This catamaran is only 9ft long and primarily intended for use by children. But read to the end to see an alternative use.

I designed the Oppikat for Nebe Boats a long time ago. They were to build it as a fibreglass production boat but didn't even start to build the moulds before closing their doors. More recently I converted the plans to a combination of plywood and strip cedar construction, to make the design more suitable for amateur builders. We have sold plans for this design to builders in 18 countries but don't know how many are sailing.

A new Oppikat is about to be launched, built by Greg Mitchell in California. She may be launched this weekend.

The newest Oppikat, ready for launch by Greg Mitchell.

Greg built it for his children from a plywood bulkhead kit but built the rest of it from the plans.

Strip planking completed, over plywood bulkheads, ready for plywood side panels.

Greg's daughter had input into the colour scheme for the new boat, choosing the colour of the cross-beams. Greg modified the tone of the blue for the hulls to a colour that would not clash. The result is very eye-catching and definitely has a female touch to it.

Hulls completed and other components assembled, ready for the rig.

This little boat is small enough to be car-topped or lashed to the trampoline of a bigger cat when towed behind the family car.

Oppikat built by Frank Nagel in Germany for his children, sailed here by his son.

Although intended for children, Frank Nagel in Germany told me that it has enough buoyancy to sail with him and two children aboard as well.

The Oppikat can be different things to different users. It fits comfortably onto the foredeck or into the davits of cruising catamarans, to serve as a tender and as a toy for both children and adults when anchored. A pair of them on a charter catamaran will add lots of scope for fun activities.

The red image is an Oppikat on the trampoline of a DH550 cruising catamaran.

For more info on this little boat go to http://dixdesign.com/oppikat.htm and to http://dixdesign.com/ for our full range of boat designs.

Assembly of the prototype Dix 470 plywood kit by Exocetus Yachts in UK is progressing nicely. This is the second hull, with improvements added into the kit since assembly of the first hull. These photos were sent to me by Exocetus.

Exocetus is able to use more advanced methods than would be used by amateur builders but the kit is set up to allow those with more basic facilities to produce comparable quality. Being the developers of the kit, they have cut all of the components themselves on their own CNC equipment. They also have a large press that they use to join multiple sheets of plywood into long panels or other large components, like bulkheads, cabin soles etc.

Sheets being joined into long hull panels by means of a press.

This long outboard hull panel was pre-assembled into one large piece before installation.

Inboard hull side fitted, with horns for major bulkheads projecting into the bridgedeck area.

Bottom panels were fitted installed.

The side panels were glued into longer lengths for convenient assembly with the equipment available to Exocetus. For my own projects and more primitive methods, I prefer to assemble skin panels in single-sheet lengths. This leaves considerably more scope for adjustment during installation to remedy any possible errors that arise due to builder error. The bottom panels were installed in single-sheet lengths, to allow accurate fitment at the centreline joint.

In the last photo above, the jigsaw joint was aligned using a strip of plywood, wrapped in plastic tape, as a temporary butt-strap. A short screw into each lobe of the jigsaw pattern ensured accurate assembly and held the joint securely until the epoxy had set.

For more info on this and our other designs, visit http://dixdesign.com/ . For more info on the kit and options, go to http://exocetus.net/ .

Kevin Bream is the owner of Exocetus Catamaran Kits in UK, the company that he formed to develop kits for our plywood catamaran designs and to market them to builders, both professional and amateur. To be sure that he does a proper job of this, he is building the Dix 470 himself, to test the fit of all parts and to develop systems to ease the whole construction process.

The number of plywood components in a boat like this is massive. Just the thought of figuring the size and shape for each one, then cutting it out before fitting it in place on the boat, can make the project being contemplated seem very intimidating. Anything that can be done to reduce the number of hours in the build and the flow of elbow grease from builder into the boat is worthy of consideration. It reduces building time for any kind of builder. For a boatyard it increases profits and for the amateur it gets him afloat and sailing sooner.

Kevin Bream has one hull completed and is now working on the second. Lessons that he learned while building the first hull have been put into making a better product. Aside from that, anyone who buys a kit from Exocetus will benefit from a product that has been built by the supplier himself. Who could provide better backup support to the builders than he who has done the development, the cutting and the building before them?

Here are recent photos of the project.

The workshop of Exocetus Catamaran Kits, first hull on the right.

Completed Dix 470 starboard hull, waiting for its mate.

Self-jigging building stocks, bolted to the concrete slab.

Interlocking bulkheads & backbone assembled, stringers in progress.

Daggerboard casing. This boat can have cruising keels or daggerboards.

Skeleton of port hull, ready for skin. The jigsaw joints are visible at panel edges.

Skeleton with side skin being dry-fitted to test for proper fit.

Stern detail of starboard hull, showing swim platform.

Exocetus Catamaran Kits can also supply similar kits for the bigger sister, the DH550.

To see more about these designs, as well as others of all types and materials, please visit http://dixdesign.com/

We have added an option of cruising fin keels to the DH550 performance cruising catamaran design. The plans continue to show the daggerboards that were originally in the design and additional drawings are now included to show the fixed keels.


Daggerboards offer improved windward performance and the ability to pull the boards up for beaching and for side-slipping in extreme weather. Cruising keels offer simpler sailing.

This option will also be available on the smaller sister, the Dix 470, when any builder wants that feature.

Visit http://dixdesign.com/ to see all of our designs.

Dudley