Larger Steel version of PARADOX

I have some experience with tandem 'Dagger Boards' and Thor Hyerdal also used them successfully on the balsa raft to control direction in the trades quite well. Yes, indeed you can control direction using the dagger boards deferentially. Any way you can spread the rig, or lateral resistance, along the boat helps both directional stability and the ability to control direction. It's why I now favor double mast rigs for cruising, having had my fill of racing (though I still race every second weekend all year) on single stick rigs.

I also used a thick steel plate as a bottom/ballast in the distant past. I wrote about it in this forum I think. Attaching ply to steel, you need many small fastenings, I use 1/4" or 3/8" at 4" centers, though I always try to have a thin steel flange for the actual interface to the plywood. I used liberal amounts of tar in my joint, messy and cheap then, probably illegal now. I 'galvanized' the steel using hot caustic soda (I think), and a hot Zink compound.
Many people on this forum are horrified at using steel in this way, as corrosion is always an issue.

Remember, you bolt a lead keel to a wooden boat, but you attach (bolt), a wooden boat to a steel keel. The steel really does form the strength member, especially at 1"+ thick. No stiffners needed.

 

From personal experience, extremely stable, but it must be fairly flat mud, sand, or shingle. Left in the water, crustations can grow in the CB well. When dried out on the tide, not so much.