12 May, 2010
In the left, a design showing the main system, based in the yuloh. At right, another fin free of motion to generate a vortex to rear. This is very schematic, cause the final angles, sizes, proportion and material will depend of the practice. But the concept is to use as less as possible any kind of mechanism under water to avoid drag.
The "yuloh" type use the lateral motion of the boat, while the other one the pounding. I think total is bigger than the add of parts in this case specially. Now I have to get it working.