Defining "Stiff"
Probably not news to anyone reading/posting here, but...
I can remember some occasions when I have tried to reason with newer sailors over their definition of "stiffness" and how it related to a boat being "tippy" and how this was not proof one way or the other as to a given boat being "stable" or not.
Boring History: Back when I was first learning I went sailing on a friend's Aquarius 23. The owner loved the roomy interior with a real Head Compartment. He said it was
very stable. Thing was, it had a firm chine and so was indeed "stiff and stable" when one stepped aboard. Under sail, though, it was wicked... get hit by a puff and the boat would heel over quickly and pop most of the rudder out of the water and round up suddenly. Even though my sailing knowledge was mostly from reading and a little dinghy sailing on nice days, I sensed that this was just
wrong.
We soon were shopping for our own trailerable, and after trying some flat bottom boats like the SJ-21, and thinking about the meaning of stability, started looking for a boat with
Final Stability and decided
not to focus on
Initial Stability. In the NW, in the 70's, that naturally led us to a Ray Richards-designed Ranger 20.
It would heel down several degrees when you stepped aboard at the dock, and heel over quickly to about 15% to 18% beating to weather. Getting water on the side deck, though, was
very difficult. In contrast to other small cruisers that (in our opinion) would deceived you with their "feel" when you boarded and then heel over God-knows-how-far under sail in stronger winds, we felt like those boats were not nearly as "Stiff" as our Ranger.
From looking at several E-31's and spending a little time on one, That design looks to me to have slack bilges. I would guess (and it's only my SWAG) that it gets board-stiff when heeled down to its designed sailing lines.
BTW, not to disparage firmer chines, either... it does all depend on the design as a
whole, with ballast ratio, beam-length, and some other etc. taken into account.
This last Saturday, on a 20 mile cruising race to windward with the later afternoon winds peaking at about 18 kts, we never got water on the side deck (135% genny) and a friend with an earlier IOR-shape Yamaha 33 running his plastic 150% genny never wetted the deck either... but a higher performance G&S designed 35 footer flushed their side decks several times.
Subtle stuff, both science and art, go into yacht design. And that is what I would imagine would make the BK-designed E-31 quite stiff and confidence-inspiring as it heals to its lines. But you all knew that!
Loren