Okay, I have what I think is a good research question.
I purchased this video that was on super sale ($6.00) from the WoodenBoat Store. It is called "Yachting in the 1930's". Boy, what a great video. It shows clips of some great boats like Dorade, and several J-Boats, and many others; some really spectacular footage.
anyway, in one section of the video it talks about various sail configurations of the time, and the spinnakers were not the balloon type that is currently in fashion, but rather a triangular type that does not go past the fore-stay. I believe the Herreshoff 12 1/2 originally had this older style spinnaker, as I think I read that the H-12 association allows the use of either style during races.
So, finally getting to my question, does anyone know what year the newer balloon style spinnaker would have been developed, and when the H 12 1/2s would have started using them?