Of course the LCG it is aft of where it was on the ORIGIONAL HULL. But, you guys are responding to my post, which I origionally explained that putting a cockpit extension made the LCG too far foward and if you didn't have the boat trimmed correctly it would ride bow heavy and behave horribly in a stern sea. The LCG being too far foward for the boat to ride and handle correctly..... with no correlation to the old LCG the old hull or anything. The LCG too far foward for the only hull that matters, the current hull with the cockpit extension. That being said. With just a cockpit extension, the LCG is indeed aft of the origional location on the origional hull, but not far enough aft for the new overall length for the LCG to maintain the same distance percentage from the transom to LCG as the old hull for the vessel to run with the same trim as it did before the extension. IE. the cockpit extension did not move to COG aft 10' to match the 10' added, not even close. It will ride bow heavy, and most naval architects balance that with fuel and water tanks, but as you drain them it again bounces the LCG further foward or too far aft if you have too much back there. Needless to say with a yacht with a cockpit extension you have to get very good at trimming the boat and where you draw fuel and water from. In the 65' Hatteras I gave as an example, the origional fuel tanks were mounted right at the COG, so as they drained it didn't effect the trim of the vessel hardly at all. But now with the extension they are foward of the LCG, and the cockpit tanks way aft of the LCG, so draining fluid from any tank has a big effect on the vessel's trim and the ride and handling of that vessel. Get the cockpit too light and it rides like coming in an inlet with the trim tabs all of the way down in a following sea.