Do you have any pictures of this Bill? Very interesting solution!

I am not an engineer, but the question sounds like "how much pressure do you need to a lift a 1/8 water column the distance from the bottom to the top of the transom". If the answer is more than the hull can withstand, or the pressure finds another hole to vent trough, you have a problem <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />