[Plumper]

Originally Posted by Jeff_H

I typically give this example to explain just how useless and dangerously misleading these formulas can be. If we had two boats that were virtually identical except that one had a 500 pound weight at the top of the mast. (Yes, I know that no one would install a 500 lb weight at the top of the mast.) The boat with the weight up its mast would appear to be less prone to capsize under the capsize screen formula, and would appear to be more comfortable under the Motion Comfort ratio. Nothing would be further than the truth. That is why I see these formulas as being worse than useless. This is especially true in the case of boats with long overhangs as explained above.

Respectfully,
Jeff

That is a pretty self serving example. The formulas were developed to give some relative comparison between boats that are properly (or close to it) designed. Any designer or owner who puts 500lbs at the top of the mast is a fool. You could pull many tricks like that out of thin air and use it to fool a formula. That sort of stuff does not lend weight to your argument at all. Quite the contrary.

The fact is that those various formulas are still very much in use. Their usefulness has been demonstrated. Of course they don't work for oddities like your example. They also don't work for multihulls, dinghies or sailing rafts but that doesn't make them wrong. They must be used with common sense.