here it is, the long awaited 2x4.
frontside is set up with a keel fin, backside as a quad. the backside rail has a wing and is 1" longer. the concave on the twin side is based on a single concave between the fins and the concave on the quad side carries all the way to the rail from the wing back. i'll let you know how it goes. can't wait, hope to prove all you skeptics wrong. one disadvantage already.....it does not stand up straight!