Sail area / Displacement ratio

An article from AES

A lot of designers (and journalists) put great store by the sail area to displacement ratio. Whilst that is their business, we think that they would be better off to consider a ratio of (mast height & sail area) to righting moment. As this is a better way of making a comparison. This ratio is a rough indication of sail power (overturning moment) to yacht stability (righting moment). The problem with the sail area displacement ratio is that it fails to take into account stability generated by beam or form, draft nor aspect ratio of sail plan (distance from CLR to CoE). Clearly a beamy yacht with low aspect sail plan can handle a lot more sail area for its displacement than a narrow yacht with a tall mast. So the alternative is Sail Area x Height to CoE / RMC. This ratio will soon start to give some feedback on whether the yacht can handle its sail plan and we think it is a better form of comparison when comparing two similar yachts. I was recently informed that the ratio I am discussing is an upside down dellenbaugh angle, which is fine with us.