I have been looking at this double dory catamaran model I designed and built for twenty-seven years now and lately I've been thinking about actually building it full sized. Since its just two dory hulls strapped together, it should go together quickly and cheaply.
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In 2008 I showed the model to Phil Bolger at the Mystic Seaport WoodenBoat Show outside the restaurant right before we all went in to the Bolger tribute dinner. Mr. Bolger said that my double dory reminded him of his catamaran oyster carrier. He asked about the sunshade and I explained how easily I get sunburned. He said that with all that wetted surface you may not need any daggerboards. He also said, “I like it.” As other people demanded his attention and he turned, I floated away on cloud nine with his last three words. My longtime hero naval architect had said he liked something that I had designed. That is something that no one can ever take away from me.
In truth, I can’t take much credit for the design because basically it is just two instant boats strapped together. It was my “cheapness” that decided to use the 2’ high sides because that’s basically what you get when you rip a ply sheet down the middle. The boat, after that decision, pretty much designed itself. I just stepped down the bow and the stern decks somewhat to eliminate some of the windage. I am certainly no naval architect – just an inventive model builder. Here it is from an old black and white print when it still had it's sail rig.
Many is the night that this double dory model has successfully navigated the storm tossed covers of my bed. What we are talking about here is only seven or eight sheets of plywood and all the connecting arms are straight solid laminations (fir). I could buy everything I need for the build here in town. With a nod towards James Wharram and the Polynesians, she could be lashed together for flexible strength. Using the sail rig from another boat (I think I have a birdwing mast laying around somewhere) and local marine fir, I should be able to build the basic boat for about $2000 – thus the name Down and Dirty Double Dory. I also have this crazy idea that my life is more important than the life of a cheap plywood boat so I'm inclined to pour enough foam into the design to make her unsinkable and self-bailing. She could live on a mooring and be ready to sail at the drop of a hat.
It would be neat to have both the boat and the rig be my design. I really think I should build it. It should give Ray's Slider a good run for the money. I'm retired. What else am I gonna do???
Hey James,
Thanks for the encouragement. I agree she would tack better and sail better in light air with more rocker aft but I'm interested in that funky physics that multihulls exhibit where they sail faster than their hulls should allow – that slippery gray area that no one can quite explain. I'm also hopeful that in the right conditions she will plane with one hull flying but we will see about that. As things are, the sides are 2' x 16' with no need to cut on the bottom edge at all. The top edges are notched down at the bow and the stern to reduce windage. Also I have the idea to build it exactly like the model because that's what Bolger said he liked and I want to find out how she would perform as designed. With my little 4HP four-stroke running, it would also be interesting to see how well it would motorsail. Can't let her heel too much with the motor running because it's a fourstroke and you don't want to starve the valves of oil but sailed flat with a motor assist would probably yield some efficient numbers for gasoline mileage. And many times, early morning when the fish are biting, there ain't no wind anyways. Anyone know how much heel angle a little 4HP four-stroke can take and still operate correctly (getting oil to the valve train)?
There will definitely be daggerboards in use for windward work. With the poured in foam on the inside of the bottom, a daggerboard box can be ripped apart on a hard grounding and not affect the boat's ability to float.
The decision I'm really struggling with is what kind of plywood to use. I wanted to do the boat entirely in North American native wood (Douglas fir) but I'm having trouble finding 1/4" marine fir. I could do the whole boat in 3/8" fir ply but by the time I pour the foam in on the inside and glass the outsides, 1/4" fir ply would have been plenty stiff enough and better at keeping the weight down. I may switch back to mahogany ply because I really like how my existing tan bark sails look with sapelle mahogany and I already have six sheets or so of sapelle laying around from the last boat I almost built.![]()