Thanks Mike, I already have a boom vang, ready to use. When going dead downwind, or almost so, I ill simply pass it under the forward aka and cleat it to the small cleat beside the seat. But when sailing closer to the wind....well I haven't figured that one out yet. I will just have experiment with that but I don't think I will have any problem with cleating it down somewhere.
I sat my AI up in my yard and pointed it dead downwind. Then without the boom, the sail would do nothing. I simply cold not get it to hold wind at all. It kept wrapping around the mast. Then I installed the boom, along with the boom vang and it worked wonders. The wind suddenly grabbed the AI and swung it around before I could react. Scared the crap out of me but nothing was damaged. Here is a picture I was snapping just as the wind caught it and began spinning it around. You can see the boom vang attached.