Inclining Experiment
John S -As far as the piece about heeling your boat over and checking on it's righting moment, etc., I believe you are referring to what is called an "Inclining Experiment" - at least on ships. In the Navy, ships undergo inclining experiments at the time they are built, and again as part of the testing that goes into any major equipment change (weight redistribution). They literally crane huge weights onto the ship, then proceed to move them around taking very careful measurement of how far the ship heels in each configuration. From this data, they figure out center of gravity, center of bouyancy, metacentric height, etc. - ultimately, how far can this ship roll over and still come back up rather than capsize. On my first ship, we had large gun turrets port and starboard, which weighed around 150 tons each as I recall, and were located pretty high above the water - they were actually designed so that the downhill one would fall off the ship at 57 degrees of heel, the idea being that the sudden loss of tonnage on the down side would give the ship a last-minute "boost" to get back upright. Of course, this could only work for one roll, but I always thought it was pretty ingenious - later on when the guns became obsolete and were removed from the ships altogether, I believe the point at which the ship would capsize became 59 degrees.Anyway, what you are proposing may be far less precise, but it is not unheard of in boat building. I'm guessing that with no water in the tank, you'll get positive righting moment close to 80 degrees (assuming zero wind, calm water, and sails down) but once the mast hits the water she'll turtle, and once turtled you're going to need special equipment to right her. I don't see where a Mac could be righted by standing on the centerboard like you do on a Sunfish, Laser, 470, etc. For the person above who mentioned that once the cabin is partially full, the boat would come up because you've got some ballast - well, that doesn't work. For the ballast to function as ballast it needs to be confined to the correct volume - i.e. the tank. Any other water inside the hull is generally called flooding, or if you don't wish to report that you have flooding, it is called "unwanted water" **grin**- AndyS