[seabreeze_97]

"To some extent, the source of the inertia is important as well. For example, we can compare two otherwise exactly identical boats, each with equal roll moments of inertia, but one has a heavy mast but less ballast by the same amount added to the rig while the other has a lighter mast and heavier ballast. The high vertical center of gravity of the mast would tend to cause the first boat to roll further than the second boat for an equal roll loading, because the weight in the mast would be on the motion side of the roll axis while the weight in the keel would be on the opposing side of the roll axis."

Well, yeah, but why would anyone take a heavier rig and subtract the additional weight of said rig from their ballast? They wouldn't. You said it yourself, all else being equal. Removing ballast makes what you say true, but, again, why do that when it flies in the face of good sense. We aren't talking about dinghys on the pond here. So, as determined by the Fastnet committee, a heavier rig allows for greater resistance to capsize thanks to the very inertia you mention. A heavier hull also contributes to this, as does the lowest possible center of gravity, which comes back to the question of why would anyone remove valuable ballast because of a heavier rig? The Fastnet crews didn't abandon ship for motion comfort issues (fore and aft), they were rolling severely, some being rolled 360 degrees, with many having difficulty righting after capsize. While stability offers comfort, it wasn't a study on motion comfort, it was about stability and capsize.

As usual, Jeff, you just have to throw a jab at the CCA. It has been noted that most of the boats that got into serious trouble in the Fastnet race would not have met the minimum size limit of the CCA Bermuda race.... because size matters. It should also be noted that among the smaller boats, those built before 1975 survived with few problems, while many of the (then) new boats suffered badly. Something had changed and later statistical data confirmed that. "Boats everywhere were becoming lighter, beamier, and less stable."

Now, no doubt all this led to designers re-thinking things, but a plumb bow and fat behind cannot act in place of weight and the inertia that comes with it.