I know this is old but I’ll take a stab at it.
What does it translate to…I thought about that and it’s a great question. The ratio itself is simple, it’s the weight of the ballast relative to the weight of the whole boat.
Your question, posed another way, I think is, what would be different between two similar boats with very different b/d ratios?
The only thing I can think of is if you have a boat with a smaller radio, or, less difference between the weight of the ballast versus total weight, then you might have less stability, a lower comfort ratio, and worse capsize recovery ability. I’m guessing, just to start a conversation which might draw out the guy who knows!
I’m curious about the purpose of “double enders” or “canoe” stern boats?